<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:0aa08858-0f3d-4f50-aebd-dec3ec9d72e8,g:67d31378-fc97-47e4-a431-399d52be3b1b-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://acmrcsh.com/role/CoverPage" xlink:type="simple" xlink:href="acmr-20240331.xsd#CoverPage"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/CoverPage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_25bacd18-865b-4fdd-b9aa-9e03244e06e7" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_DocumentInformationTable_25bacd18-865b-4fdd-b9aa-9e03244e06e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_46f2c9bb-7d8a-43f5-b6e5-fff9bbe8b54a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_25bacd18-865b-4fdd-b9aa-9e03244e06e7" xlink:to="loc_us-gaap_StatementClassOfStockAxis_46f2c9bb-7d8a-43f5-b6e5-fff9bbe8b54a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_46f2c9bb-7d8a-43f5-b6e5-fff9bbe8b54a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_46f2c9bb-7d8a-43f5-b6e5-fff9bbe8b54a" xlink:to="loc_us-gaap_ClassOfStockDomain_46f2c9bb-7d8a-43f5-b6e5-fff9bbe8b54a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_87fdf576-9d9e-4909-bff5-e8378bec6575" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_46f2c9bb-7d8a-43f5-b6e5-fff9bbe8b54a" xlink:to="loc_us-gaap_ClassOfStockDomain_87fdf576-9d9e-4909-bff5-e8378bec6575" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_d161c5d9-b588-4899-b852-eb6e74992a1e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_87fdf576-9d9e-4909-bff5-e8378bec6575" xlink:to="loc_us-gaap_CommonClassAMember_d161c5d9-b588-4899-b852-eb6e74992a1e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_ddc58090-9551-40a7-9569-a4dd8504b2be" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_87fdf576-9d9e-4909-bff5-e8378bec6575" xlink:to="loc_us-gaap_CommonClassBMember_ddc58090-9551-40a7-9569-a4dd8504b2be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_9a25bea1-2579-405a-be30-8a7dba57b7b0" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_DocumentType_9a25bea1-2579-405a-be30-8a7dba57b7b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_6eb96b9c-c1d8-4137-b818-fa1c5f4aefd5" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_DocumentQuarterlyReport_6eb96b9c-c1d8-4137-b818-fa1c5f4aefd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_28b74d04-30cf-41db-854a-f74ed48553c8" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_DocumentPeriodEndDate_28b74d04-30cf-41db-854a-f74ed48553c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_f58847e5-4cc7-4114-bbd4-c3f0c8372811" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_DocumentTransitionReport_f58847e5-4cc7-4114-bbd4-c3f0c8372811" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_5600ee4d-1a59-4209-92a3-263a1d97f549" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityFileNumber_5600ee4d-1a59-4209-92a3-263a1d97f549" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_de362045-0571-4640-9c91-3cc9ae931d95" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityRegistrantName_de362045-0571-4640-9c91-3cc9ae931d95" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_648db000-b20b-42ee-adb3-cd2886afacdc" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityIncorporationStateCountryCode_648db000-b20b-42ee-adb3-cd2886afacdc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_9a64499d-9cfe-47c6-bd7d-0a3de577033e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityTaxIdentificationNumber_9a64499d-9cfe-47c6-bd7d-0a3de577033e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_e9343978-68b3-4f7a-acbd-da6c2e6931da" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityAddressAddressLine1_e9343978-68b3-4f7a-acbd-da6c2e6931da" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_355e5e78-6e70-4e12-a361-228edf840c24" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityAddressCityOrTown_355e5e78-6e70-4e12-a361-228edf840c24" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_31c39387-bcb1-457f-9baa-8bc5e45b3c53" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityAddressStateOrProvince_31c39387-bcb1-457f-9baa-8bc5e45b3c53" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_d8f58f45-0cf5-4e87-b7ef-d3607985e9fe" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityAddressPostalZipCode_d8f58f45-0cf5-4e87-b7ef-d3607985e9fe" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_0c29a230-25ac-4e5f-9ca6-104c676c425b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_CityAreaCode_0c29a230-25ac-4e5f-9ca6-104c676c425b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_963dfe3e-1e74-4f6e-b223-f8cfd2dedbea" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_LocalPhoneNumber_963dfe3e-1e74-4f6e-b223-f8cfd2dedbea" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_7b0413a3-e2e0-4cc6-8a11-22d034ae01d6" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_Security12bTitle_7b0413a3-e2e0-4cc6-8a11-22d034ae01d6" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_de1778e4-424a-41cc-bc90-9488d341889e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_TradingSymbol_de1778e4-424a-41cc-bc90-9488d341889e" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_8339814e-1ccb-4b0d-8816-1731f3b669e7" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_SecurityExchangeName_8339814e-1ccb-4b0d-8816-1731f3b669e7" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_c02d0a28-ff2c-4dea-8c0f-fcf32326f73f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityCurrentReportingStatus_c02d0a28-ff2c-4dea-8c0f-fcf32326f73f" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_6a775edb-4381-48d9-abdf-11c6bb81d072" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityInteractiveDataCurrent_6a775edb-4381-48d9-abdf-11c6bb81d072" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_82f1f7f0-f527-4921-a7aa-13abf5f06a3c" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityFilerCategory_82f1f7f0-f527-4921-a7aa-13abf5f06a3c" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_8341682e-ad70-44e6-909b-3e0d906a0baf" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntitySmallBusiness_8341682e-ad70-44e6-909b-3e0d906a0baf" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_a06756e6-6af3-482b-828a-f4715331eed1" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityEmergingGrowthCompany_a06756e6-6af3-482b-828a-f4715331eed1" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_faf013d9-025b-4cce-a558-eaaba89885de" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityShellCompany_faf013d9-025b-4cce-a558-eaaba89885de" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_ff450ec2-3738-46be-ad5d-1c0a9eb7af5e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_ff450ec2-3738-46be-ad5d-1c0a9eb7af5e" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_a1cbb96b-3a6c-4a2b-b696-37398914e04c" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_EntityCentralIndexKey_a1cbb96b-3a6c-4a2b-b696-37398914e04c" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_a9fd7f96-c78d-417b-82e3-81d17c1f5540" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_DocumentFiscalYearFocus_a9fd7f96-c78d-417b-82e3-81d17c1f5540" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_5040c05d-6399-4d17-9d81-482125ec97ef" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_AmendmentFlag_5040c05d-6399-4d17-9d81-482125ec97ef" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_fcbbc1e0-257f-4ba4-bdb8-6d04d75f2dd7" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_CurrentFiscalYearEndDate_fcbbc1e0-257f-4ba4-bdb8-6d04d75f2dd7" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_914e0573-4f86-4a8c-b1ce-11c73140f42f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_a31224dc-f6e6-4b53-94eb-a79f7ca40383" xlink:to="loc_dei_DocumentFiscalPeriodFocus_914e0573-4f86-4a8c-b1ce-11c73140f42f" xlink:type="arc" order="28"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/CondensedConsolidatedBalanceSheets" xlink:type="simple" xlink:href="acmr-20240331.xsd#CondensedConsolidatedBalanceSheets"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_5adb552b-1830-43f9-bc6d-1b262b3d5767" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_3d958e25-17c6-4db1-817f-cf96cffa5247" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_5adb552b-1830-43f9-bc6d-1b262b3d5767" xlink:to="loc_us-gaap_StatementTable_3d958e25-17c6-4db1-817f-cf96cffa5247" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_1869d54c-2eb9-4048-979d-cc3ebaaff899" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_3d958e25-17c6-4db1-817f-cf96cffa5247" xlink:to="loc_us-gaap_StatementClassOfStockAxis_1869d54c-2eb9-4048-979d-cc3ebaaff899" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_1869d54c-2eb9-4048-979d-cc3ebaaff899_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_1869d54c-2eb9-4048-979d-cc3ebaaff899" xlink:to="loc_us-gaap_ClassOfStockDomain_1869d54c-2eb9-4048-979d-cc3ebaaff899_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_7463ca16-1493-4267-989d-d0fa0f2843ba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_1869d54c-2eb9-4048-979d-cc3ebaaff899" xlink:to="loc_us-gaap_ClassOfStockDomain_7463ca16-1493-4267-989d-d0fa0f2843ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_c8c136b1-4aea-446c-8385-c65e256e6dab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_7463ca16-1493-4267-989d-d0fa0f2843ba" xlink:to="loc_us-gaap_CommonClassAMember_c8c136b1-4aea-446c-8385-c65e256e6dab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_5e7a18a9-0a1e-4548-ba7e-31fb484bbfea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_7463ca16-1493-4267-989d-d0fa0f2843ba" xlink:to="loc_us-gaap_CommonClassBMember_5e7a18a9-0a1e-4548-ba7e-31fb484bbfea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_7fbb635b-c3bb-47ad-9733-706ff550a3df" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_3d958e25-17c6-4db1-817f-cf96cffa5247" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_7fbb635b-c3bb-47ad-9733-706ff550a3df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_7fbb635b-c3bb-47ad-9733-706ff550a3df_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_7fbb635b-c3bb-47ad-9733-706ff550a3df" xlink:to="loc_us-gaap_RelatedPartyDomain_7fbb635b-c3bb-47ad-9733-706ff550a3df_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_1220508b-c2a8-4679-836f-19a61b54bf47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_7fbb635b-c3bb-47ad-9733-706ff550a3df" xlink:to="loc_us-gaap_RelatedPartyDomain_1220508b-c2a8-4679-836f-19a61b54bf47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_3de9c32b-c3da-474c-96d0-b1094b5e0164" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_1220508b-c2a8-4679-836f-19a61b54bf47" xlink:to="loc_us-gaap_RelatedPartyMember_3de9c32b-c3da-474c-96d0-b1094b5e0164" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_270a5e40-b462-4979-a8f8-be75f63f77cf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_1220508b-c2a8-4679-836f-19a61b54bf47" xlink:to="loc_us-gaap_NonrelatedPartyMember_270a5e40-b462-4979-a8f8-be75f63f77cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5adb552b-1830-43f9-bc6d-1b262b3d5767" xlink:to="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_7c0a42f9-b30d-4c6d-b03c-7dd8bb171fe4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_7c0a42f9-b30d-4c6d-b03c-7dd8bb171fe4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashCurrent_fc835142-fc63-402b-a029-4c022a91e496" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedCashCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_RestrictedCashCurrent_fc835142-fc63-402b-a029-4c022a91e496" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsAssetsCurrent_59a70c23-9e33-4287-a78c-8710b00408dc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepositsAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_DepositsAssetsCurrent_59a70c23-9e33-4287-a78c-8710b00408dc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_cbe5a152-6967-4268-8706-fd5e83be3f07" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_ShortTermInvestments_cbe5a152-6967-4268-8706-fd5e83be3f07" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_bac36715-4ab4-43f0-a2fe-7e355061a185" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_bac36715-4ab4-43f0-a2fe-7e355061a185" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherReceivablesNetCurrent_bea9ee16-6f90-4ba1-9d42-bd22ccd39a0c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherReceivablesNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_OtherReceivablesNetCurrent_bea9ee16-6f90-4ba1-9d42-bd22ccd39a0c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_0788a333-9563-4c9a-bc6f-db81c1d0890f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_InventoryNet_0788a333-9563-4c9a-bc6f-db81c1d0890f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseCurrent_2176fe6f-eecb-4432-a3b1-4278e305f902" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_PrepaidExpenseCurrent_2176fe6f-eecb-4432-a3b1-4278e305f902" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_a4b25ce4-95b9-4c51-858e-488ff9800072" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f0e69ac6-3dc6-4f97-acdc-8537493f89fc" xlink:to="loc_us-gaap_AssetsCurrent_a4b25ce4-95b9-4c51-858e-488ff9800072" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_f21b23ae-aca4-4da2-a8da-86db19801a4b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_f21b23ae-aca4-4da2-a8da-86db19801a4b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LandUseRightNet_e4504568-7357-48e1-9537-6b80a56ec1dc" xlink:href="acmr-20240331.xsd#acmr_LandUseRightNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_acmr_LandUseRightNet_e4504568-7357-48e1-9537-6b80a56ec1dc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_6fe30fce-9993-49e4-8372-636aa3af931f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_6fe30fce-9993-49e4-8372-636aa3af931f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c813d55e-3380-4405-9d43-d5e8db732667" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c813d55e-3380-4405-9d43-d5e8db732667" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsAssetsNoncurrent_e85350fd-c1ff-45a7-b7c1-2ca02f7f71ba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepositsAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_DepositsAssetsNoncurrent_e85350fd-c1ff-45a7-b7c1-2ca02f7f71ba" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_ea9bd038-7546-45ec-85d1-8e8d60546189" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_ea9bd038-7546-45ec-85d1-8e8d60546189" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_130d5bcf-3998-40a0-80f1-1bde5852c22f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_LongTermInvestments_130d5bcf-3998-40a0-80f1-1bde5852c22f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_af275721-f30f-4116-b21a-c6d2de9d5ce0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_af275721-f30f-4116-b21a-c6d2de9d5ce0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_55a2000d-07f5-4317-8ead-637ea0904315" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_726fa6ae-390f-4ff2-8205-9a78b0fcf751" xlink:to="loc_us-gaap_Assets_55a2000d-07f5-4317-8ead-637ea0904315" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5adb552b-1830-43f9-bc6d-1b262b3d5767" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_e8a49b7e-2e49-4b12-9a08-bd534bf157b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_ShortTermBorrowings_e8a49b7e-2e49-4b12-9a08-bd534bf157b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_9ac0fc6d-a09a-4c75-a584-ea6ef69bfff8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_LongTermDebtCurrent_9ac0fc6d-a09a-4c75-a584-ea6ef69bfff8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_1f76499f-bf52-4f82-a4be-64426ff6efb8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_AccountsPayableCurrent_1f76499f-bf52-4f82-a4be-64426ff6efb8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_31759185-16d4-4f5a-9015-5b03f7c1e487" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_31759185-16d4-4f5a-9015-5b03f7c1e487" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeCurrent_5268b598-c6c4-4f23-84aa-26e4193604ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredIncomeCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_DeferredIncomeCurrent_5268b598-c6c4-4f23-84aa-26e4193604ff" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_165a2831-6b48-41d3-8f94-b7914ced4f2a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedIncomeTaxesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_165a2831-6b48-41d3-8f94-b7914ced4f2a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_IncomeTaxesCurrentPayableAndDeferredTaxLiabilities_2e6e759f-3b84-4f21-83c5-3d74f872e953" xlink:href="acmr-20240331.xsd#acmr_IncomeTaxesCurrentPayableAndDeferredTaxLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_acmr_IncomeTaxesCurrentPayableAndDeferredTaxLiabilities_2e6e759f-3b84-4f21-83c5-3d74f872e953" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAccountsPayableAndAccruedLiabilities_0bbb7f25-cd76-4b2f-a783-169a19bd99de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAccountsPayableAndAccruedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_OtherAccountsPayableAndAccruedLiabilities_0bbb7f25-cd76-4b2f-a783-169a19bd99de" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_ec1f3809-f86f-4039-9666-463ea0b8a5ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_ec1f3809-f86f-4039-9666-463ea0b8a5ee" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_d2ada13d-57d5-4cfd-972b-14ac2a1ee5b6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b1582e96-1bc6-4c14-a25f-fd47c26b368a" xlink:to="loc_us-gaap_LiabilitiesCurrent_d2ada13d-57d5-4cfd-972b-14ac2a1ee5b6" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_dc36fbf5-6962-46f2-8e28-9095930d14e8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_dc36fbf5-6962-46f2-8e28-9095930d14e8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_c8a9baf7-07ec-48d4-8241-d61dd712bd63" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_c8a9baf7-07ec-48d4-8241-d61dd712bd63" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_8f3a824d-38fa-4e51-a7db-ad6777df2a22" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_8f3a824d-38fa-4e51-a7db-ad6777df2a22" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_1244f09c-7ebe-4dd8-a683-dcd67eb6ba35" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:to="loc_us-gaap_Liabilities_1244f09c-7ebe-4dd8-a683-dcd67eb6ba35" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_7b056882-2a1e-429a-84f4-22872746ae95" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:to="loc_us-gaap_CommitmentsAndContingencies_7b056882-2a1e-429a-84f4-22872746ae95" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:to="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_b7f17c62-419c-4aaf-96e7-701b17d74a21" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:to="loc_us-gaap_CommonStockValue_b7f17c62-419c-4aaf-96e7-701b17d74a21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_33c523f3-a741-4f94-8f9e-4cf038ccf7f7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:to="loc_us-gaap_AdditionalPaidInCapital_33c523f3-a741-4f94-8f9e-4cf038ccf7f7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_94cce0e3-85f9-4df6-a383-2b4fe1da07b2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_94cce0e3-85f9-4df6-a383-2b4fe1da07b2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance_871aaaee-a92e-4022-b5b3-36813d447330" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:to="loc_us-gaap_StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance_871aaaee-a92e-4022-b5b3-36813d447330" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_11735aa6-3160-470a-bbb9-0d4fd51b9836" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_11735aa6-3160-470a-bbb9-0d4fd51b9836" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_765e1031-7a67-43a4-8a45-c8a7d6279396" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:to="loc_us-gaap_StockholdersEquity_765e1031-7a67-43a4-8a45-c8a7d6279396" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_fe27afba-baf1-4ba7-a8af-351cc1b33280" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:to="loc_us-gaap_MinorityInterest_fe27afba-baf1-4ba7-a8af-351cc1b33280" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_cc3d6aff-19dc-40e3-8d97-b1de6e46d48c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_f83c78c7-ba23-4401-8485-5b266b7a536c" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_cc3d6aff-19dc-40e3-8d97-b1de6e46d48c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_649b0766-508e-433f-b745-553bca82e633" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_0d8794ae-d142-45a1-bcdd-81bbe9e597aa" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_649b0766-508e-433f-b745-553bca82e633" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/CondensedConsolidatedStatementsofOperationsandComprehensiveIncomeLossParenthetical" xlink:type="simple" xlink:href="acmr-20240331.xsd#CondensedConsolidatedStatementsofOperationsandComprehensiveIncomeLossParenthetical"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/CondensedConsolidatedStatementsofOperationsandComprehensiveIncomeLossParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_29a58480-b9c5-4e69-81c3-b57560edaafe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_ee5ce288-6e91-4130-b7a2-2ca2ef66f80b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_29a58480-b9c5-4e69-81c3-b57560edaafe" xlink:to="loc_us-gaap_StatementTable_ee5ce288-6e91-4130-b7a2-2ca2ef66f80b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_052313c1-9be2-408a-a6a1-68103492b9e7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_ee5ce288-6e91-4130-b7a2-2ca2ef66f80b" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_052313c1-9be2-408a-a6a1-68103492b9e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_052313c1-9be2-408a-a6a1-68103492b9e7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_052313c1-9be2-408a-a6a1-68103492b9e7" xlink:to="loc_us-gaap_RelatedPartyDomain_052313c1-9be2-408a-a6a1-68103492b9e7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_d48d8727-4550-425e-a644-6e01c54b0473" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_052313c1-9be2-408a-a6a1-68103492b9e7" xlink:to="loc_us-gaap_RelatedPartyDomain_d48d8727-4550-425e-a644-6e01c54b0473" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_f1f56da1-9d38-4ad5-bd14-041b5812a562" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_d48d8727-4550-425e-a644-6e01c54b0473" xlink:to="loc_us-gaap_RelatedPartyMember_f1f56da1-9d38-4ad5-bd14-041b5812a562" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_ea802d32-b117-42fb-828e-282462df52d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_29a58480-b9c5-4e69-81c3-b57560edaafe" xlink:to="loc_us-gaap_CostOfRevenue_ea802d32-b117-42fb-828e-282462df52d3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/CondensedConsolidatedStatementsofChangesinEquity" xlink:type="simple" xlink:href="acmr-20240331.xsd#CondensedConsolidatedStatementsofChangesinEquity"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/CondensedConsolidatedStatementsofChangesinEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_e9b4b799-054a-4519-b224-6738e7d828b4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_0226f817-30ee-44bb-99ea-b941b36bb5bd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_e9b4b799-054a-4519-b224-6738e7d828b4" xlink:to="loc_us-gaap_StatementTable_0226f817-30ee-44bb-99ea-b941b36bb5bd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_fd0c38a6-f543-4f85-9bbf-d8dd715c70f1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0226f817-30ee-44bb-99ea-b941b36bb5bd" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_fd0c38a6-f543-4f85-9bbf-d8dd715c70f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_fd0c38a6-f543-4f85-9bbf-d8dd715c70f1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_fd0c38a6-f543-4f85-9bbf-d8dd715c70f1" xlink:to="loc_us-gaap_EquityComponentDomain_fd0c38a6-f543-4f85-9bbf-d8dd715c70f1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_82546851-6348-42c1-bf28-6e2bc2574356" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_fd0c38a6-f543-4f85-9bbf-d8dd715c70f1" xlink:to="loc_us-gaap_EquityComponentDomain_82546851-6348-42c1-bf28-6e2bc2574356" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_dc449ba9-92fc-40fb-8003-23c7a28d21ea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_82546851-6348-42c1-bf28-6e2bc2574356" xlink:to="loc_us-gaap_CommonStockMember_dc449ba9-92fc-40fb-8003-23c7a28d21ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_a4b06094-e4f3-49a8-b480-b745ab6fb221" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_82546851-6348-42c1-bf28-6e2bc2574356" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_a4b06094-e4f3-49a8-b480-b745ab6fb221" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_2d20a676-41b4-41c3-addb-8d72c2cbd756" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_82546851-6348-42c1-bf28-6e2bc2574356" xlink:to="loc_us-gaap_RetainedEarningsMember_2d20a676-41b4-41c3-addb-8d72c2cbd756" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAppropriatedMember_34119f60-08d1-477a-abbb-be0de56f3695" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAppropriatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_82546851-6348-42c1-bf28-6e2bc2574356" xlink:to="loc_us-gaap_RetainedEarningsAppropriatedMember_34119f60-08d1-477a-abbb-be0de56f3695" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_67480ea8-1823-48d8-ac1f-2072f27f8719" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_82546851-6348-42c1-bf28-6e2bc2574356" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_67480ea8-1823-48d8-ac1f-2072f27f8719" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_f093a6fc-73c8-4d15-becb-c11288a7b69f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_82546851-6348-42c1-bf28-6e2bc2574356" xlink:to="loc_us-gaap_NoncontrollingInterestMember_f093a6fc-73c8-4d15-becb-c11288a7b69f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_6afcdae7-abc6-44c9-94e5-094f1e3a3b89" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0226f817-30ee-44bb-99ea-b941b36bb5bd" xlink:to="loc_us-gaap_StatementClassOfStockAxis_6afcdae7-abc6-44c9-94e5-094f1e3a3b89" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_6afcdae7-abc6-44c9-94e5-094f1e3a3b89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6afcdae7-abc6-44c9-94e5-094f1e3a3b89" xlink:to="loc_us-gaap_ClassOfStockDomain_6afcdae7-abc6-44c9-94e5-094f1e3a3b89_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_2b1b595b-9a5e-436d-96a2-e7e842ff5c1a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6afcdae7-abc6-44c9-94e5-094f1e3a3b89" xlink:to="loc_us-gaap_ClassOfStockDomain_2b1b595b-9a5e-436d-96a2-e7e842ff5c1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_44d7ceda-c93f-4e62-a81c-56a2c3b956f8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_2b1b595b-9a5e-436d-96a2-e7e842ff5c1a" xlink:to="loc_us-gaap_CommonClassAMember_44d7ceda-c93f-4e62-a81c-56a2c3b956f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_d26baf32-c1fc-49ce-970a-c59e34081805" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_2b1b595b-9a5e-436d-96a2-e7e842ff5c1a" xlink:to="loc_us-gaap_CommonClassBMember_d26baf32-c1fc-49ce-970a-c59e34081805" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_c03710e7-c106-4237-84bb-3f68ce4120c4" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0226f817-30ee-44bb-99ea-b941b36bb5bd" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_c03710e7-c106-4237-84bb-3f68ce4120c4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_c03710e7-c106-4237-84bb-3f68ce4120c4_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_c03710e7-c106-4237-84bb-3f68ce4120c4" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_c03710e7-c106-4237-84bb-3f68ce4120c4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_6f183523-f483-4762-a8b9-931fa0c49147" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_c03710e7-c106-4237-84bb-3f68ce4120c4" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_6f183523-f483-4762-a8b9-931fa0c49147" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_f84e0a77-73b4-47f4-85f7-25588eb7805a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_6f183523-f483-4762-a8b9-931fa0c49147" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_f84e0a77-73b4-47f4-85f7-25588eb7805a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_e9b4b799-054a-4519-b224-6738e7d828b4" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_3e55fa9a-9344-4252-8d11-89be7247c364" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_3e55fa9a-9344-4252-8d11-89be7247c364" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_33b8ecac-80ed-4982-b889-0a595df30ff7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_33b8ecac-80ed-4982-b889-0a595df30ff7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_b2449d3c-95b6-4fb4-b586-04fa877281c4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:to="loc_us-gaap_ProfitLoss_b2449d3c-95b6-4fb4-b586-04fa877281c4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_c03d8b9b-aeeb-4dc5-aa66-dfcba9914dea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_c03d8b9b-aeeb-4dc5-aa66-dfcba9914dea" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_5aad3e59-b252-4d03-b970-ceb2d58779e7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_5aad3e59-b252-4d03-b970-ceb2d58779e7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_ccb31edb-b83a-4efc-a5dd-b49ee3e01166" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_ccb31edb-b83a-4efc-a5dd-b49ee3e01166" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_aff6dc7f-8931-49b9-b840-1a4d1f68f06b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e79e4d37-756a-42f8-bd02-7bedf6da69f9" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_aff6dc7f-8931-49b9-b840-1a4d1f68f06b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_380230da-3c23-4136-92ba-a86a6dd13eeb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_c07cc883-471e-4c37-817e-62c0898793d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/DESCRIPTIONOFBUSINESSDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#DESCRIPTIONOFBUSINESSDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/DESCRIPTIONOFBUSINESSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems_9ca12af0-307b-439c-8ea0-5fa2fcf35c99" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_b7437106-d663-414e-8f62-1c5be2b002a2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems_9ca12af0-307b-439c-8ea0-5fa2fcf35c99" xlink:to="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_b7437106-d663-414e-8f62-1c5be2b002a2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_dc67bebd-2e38-401f-a226-613f673f67d6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_b7437106-d663-414e-8f62-1c5be2b002a2" xlink:to="loc_srt_ConsolidatedEntitiesAxis_dc67bebd-2e38-401f-a226-613f673f67d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_dc67bebd-2e38-401f-a226-613f673f67d6_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_dc67bebd-2e38-401f-a226-613f673f67d6" xlink:to="loc_srt_ConsolidatedEntitiesDomain_dc67bebd-2e38-401f-a226-613f673f67d6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_dc67bebd-2e38-401f-a226-613f673f67d6" xlink:to="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchShanghaiIncMember_6d0ceb81-3944-4a8d-bb04-d22435d14ad9" xlink:href="acmr-20240331.xsd#acmr_ACMResearchShanghaiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ACMResearchShanghaiIncMember_6d0ceb81-3944-4a8d-bb04-d22435d14ad9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchWuxiIncMember_0ad732ea-8dd0-4bb3-8fd1-aaeb05c65c6f" xlink:href="acmr-20240331.xsd#acmr_ACMResearchWuxiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ACMResearchWuxiIncMember_0ad732ea-8dd0-4bb3-8fd1-aaeb05c65c6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CleanChipTechnologiesLimitedMember_e5eb9d49-e242-43a6-b49f-92737943474d" xlink:href="acmr-20240331.xsd#acmr_CleanChipTechnologiesLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_CleanChipTechnologiesLimitedMember_e5eb9d49-e242-43a6-b49f-92737943474d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchKoreaCOLTDMember_ec255027-667f-46d9-bfcc-39008628f598" xlink:href="acmr-20240331.xsd#acmr_ACMResearchKoreaCOLTDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ACMResearchKoreaCOLTDMember_ec255027-667f-46d9-bfcc-39008628f598" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShengweiResearchShanghaiIncMember_db527076-f776-4079-bb89-b2f6c66c10ef" xlink:href="acmr-20240331.xsd#acmr_ShengweiResearchShanghaiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ShengweiResearchShanghaiIncMember_db527076-f776-4079-bb89-b2f6c66c10ef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchCAIncMember_bd0c49c5-2003-4b43-87ba-8d1160e13647" xlink:href="acmr-20240331.xsd#acmr_ACMResearchCAIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ACMResearchCAIncMember_bd0c49c5-2003-4b43-87ba-8d1160e13647" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchCaymanIncMember_8c735d9b-21e3-4477-b643-cdc02e9d9ea0" xlink:href="acmr-20240331.xsd#acmr_ACMResearchCaymanIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ACMResearchCaymanIncMember_8c735d9b-21e3-4477-b643-cdc02e9d9ea0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchSingaporePTELTDMember_88349d61-5938-4680-bae4-48c214c7f375" xlink:href="acmr-20240331.xsd#acmr_ACMResearchSingaporePTELTDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ACMResearchSingaporePTELTDMember_88349d61-5938-4680-bae4-48c214c7f375" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchBeijingIncMember_6b4c53a3-15eb-452a-b5fe-591ab110532c" xlink:href="acmr-20240331.xsd#acmr_ACMResearchBeijingIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ACMResearchBeijingIncMember_6b4c53a3-15eb-452a-b5fe-591ab110532c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_HangukACMCOLTDMember_0d7873dc-81d8-4814-b44f-e6a3d5b22c77" xlink:href="acmr-20240331.xsd#acmr_HangukACMCOLTDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_HangukACMCOLTDMember_0d7873dc-81d8-4814-b44f-e6a3d5b22c77" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_YushengMicroSemiconductorShanghaiCoLtdMember_304b3b1e-d748-4043-b018-fdbfe70299de" xlink:href="acmr-20240331.xsd#acmr_YushengMicroSemiconductorShanghaiCoLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_YushengMicroSemiconductorShanghaiCoLtdMember_304b3b1e-d748-4043-b018-fdbfe70299de" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMWooliMicroelectronicsShanghaiCoLtdMember_b72bd6e0-6d58-416a-9e16-4a6eee81b733" xlink:href="acmr-20240331.xsd#acmr_ACMWooliMicroelectronicsShanghaiCoLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7b5c1650-762f-4e10-8a61-5998c497f4e6" xlink:to="loc_acmr_ACMWooliMicroelectronicsShanghaiCoLtdMember_b72bd6e0-6d58-416a-9e16-4a6eee81b733" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_7fc5919c-fb2e-4829-a0fd-62c36c68b5af" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_b7437106-d663-414e-8f62-1c5be2b002a2" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_7fc5919c-fb2e-4829-a0fd-62c36c68b5af" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_7fc5919c-fb2e-4829-a0fd-62c36c68b5af_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_7fc5919c-fb2e-4829-a0fd-62c36c68b5af" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_7fc5919c-fb2e-4829-a0fd-62c36c68b5af_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_d65a141c-2643-41e2-9e32-7d3f74437424" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_7fc5919c-fb2e-4829-a0fd-62c36c68b5af" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_d65a141c-2643-41e2-9e32-7d3f74437424" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IPOMember_06bc7bc0-0fbd-4880-953c-3efb12177dc7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IPOMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_d65a141c-2643-41e2-9e32-7d3f74437424" xlink:to="loc_us-gaap_IPOMember_06bc7bc0-0fbd-4880-953c-3efb12177dc7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_938abd5d-95ae-4fd3-94b7-b60029643fac" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_b7437106-d663-414e-8f62-1c5be2b002a2" xlink:to="loc_us-gaap_AwardTypeAxis_938abd5d-95ae-4fd3-94b7-b60029643fac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_938abd5d-95ae-4fd3-94b7-b60029643fac_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_938abd5d-95ae-4fd3-94b7-b60029643fac" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_938abd5d-95ae-4fd3-94b7-b60029643fac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bcf40ae0-994b-4f1f-b0f9-138edab9f32c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_938abd5d-95ae-4fd3-94b7-b60029643fac" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bcf40ae0-994b-4f1f-b0f9-138edab9f32c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_e9a37d6f-53b1-49ac-9f8a-f4b041ad85f1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bcf40ae0-994b-4f1f-b0f9-138edab9f32c" xlink:to="loc_us-gaap_EmployeeStockOptionMember_e9a37d6f-53b1-49ac-9f8a-f4b041ad85f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:href="acmr-20240331.xsd#acmr_BusinessDescriptionAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems_9ca12af0-307b-439c-8ea0-5fa2fcf35c99" xlink:to="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_c8729d4f-e4f4-4976-8988-9a5a15000e9a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_c8729d4f-e4f4-4976-8988-9a5a15000e9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_PercentageAmountOfSharesOfferedFromSharesOutstanding_75bbd252-723c-4e19-b7f0-6e99a8fd2691" xlink:href="acmr-20240331.xsd#acmr_PercentageAmountOfSharesOfferedFromSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_acmr_PercentageAmountOfSharesOfferedFromSharesOutstanding_75bbd252-723c-4e19-b7f0-6e99a8fd2691" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_95f4947d-c8f4-4ef5-b0a5-34ac3de9990b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_95f4947d-c8f4-4ef5-b0a5-34ac3de9990b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_5ead5765-206a-4f6c-aa75-10c74d32e5b1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_5ead5765-206a-4f6c-aa75-10c74d32e5b1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering_edb136c5-827f-4f47-b789-5aa5656e8862" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering_edb136c5-827f-4f47-b789-5aa5656e8862" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_cd30455f-3d73-4f9e-be28-7d57cadaafe7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_cd30455f-3d73-4f9e-be28-7d57cadaafe7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_02386201-d174-4dac-918a-ca9f5f58dc2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_02386201-d174-4dac-918a-ca9f5f58dc2b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_NameOfDateOfIncorporation_8ccf9233-50a7-463e-be43-4a157b187a0f" xlink:href="acmr-20240331.xsd#acmr_NameOfDateOfIncorporation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_acmr_NameOfDateOfIncorporation_8ccf9233-50a7-463e-be43-4a157b187a0f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_SubsidiariesOwnershipPercentage_dec2e05b-5628-4214-905d-1d0eef8237a6" xlink:href="acmr-20240331.xsd#acmr_SubsidiariesOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_BusinessDescriptionAbstract_cdb5bff7-7708-4b18-9b94-9e849aad27de" xlink:to="loc_acmr_SubsidiariesOwnershipPercentage_dec2e05b-5628-4214-905d-1d0eef8237a6" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESCashandCashEquivalentsDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESCashandCashEquivalentsDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESCashandCashEquivalentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsLineItems_704a27ee-36d4-45a2-93f2-1755ac3fb518" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_3b5a9efa-cf77-40e5-b27f-aafded5f47cc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfCashAndCashEquivalentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_704a27ee-36d4-45a2-93f2-1755ac3fb518" xlink:to="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_3b5a9efa-cf77-40e5-b27f-aafded5f47cc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_51e7492e-c000-4726-896f-2e2d541907e8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_3b5a9efa-cf77-40e5-b27f-aafded5f47cc" xlink:to="loc_srt_StatementGeographicalAxis_51e7492e-c000-4726-896f-2e2d541907e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_51e7492e-c000-4726-896f-2e2d541907e8_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_51e7492e-c000-4726-896f-2e2d541907e8" xlink:to="loc_srt_SegmentGeographicalDomain_51e7492e-c000-4726-896f-2e2d541907e8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_869f75e7-58db-4dce-a982-b0bc114e7468" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_51e7492e-c000-4726-896f-2e2d541907e8" xlink:to="loc_srt_SegmentGeographicalDomain_869f75e7-58db-4dce-a982-b0bc114e7468" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_f4a01eec-98a5-4089-a3c9-601d5b997304" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_869f75e7-58db-4dce-a982-b0bc114e7468" xlink:to="loc_country_US_f4a01eec-98a5-4089-a3c9-601d5b997304" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_7ab23b1b-63cb-475c-9cb7-caf9f5f57cf3" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_869f75e7-58db-4dce-a982-b0bc114e7468" xlink:to="loc_country_CN_7ab23b1b-63cb-475c-9cb7-caf9f5f57cf3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_HK_82f68afb-af01-4e2d-a7f7-7ce187ed2186" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_HK"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_869f75e7-58db-4dce-a982-b0bc114e7468" xlink:to="loc_country_HK_82f68afb-af01-4e2d-a7f7-7ce187ed2186" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_KR_f7bc04d9-380f-4c4c-bd93-e242e3d7c216" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_KR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_869f75e7-58db-4dce-a982-b0bc114e7468" xlink:to="loc_country_KR_f7bc04d9-380f-4c4c-bd93-e242e3d7c216" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_SG_0f906220-057e-428e-b224-e7c34bf42d41" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_SG"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_869f75e7-58db-4dce-a982-b0bc114e7468" xlink:to="loc_country_SG_0f906220-057e-428e-b224-e7c34bf42d41" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_66376269-a50c-4e0e-9fb3-8928c6eb1189" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_3b5a9efa-cf77-40e5-b27f-aafded5f47cc" xlink:to="loc_srt_ConsolidatedEntitiesAxis_66376269-a50c-4e0e-9fb3-8928c6eb1189" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_66376269-a50c-4e0e-9fb3-8928c6eb1189_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_66376269-a50c-4e0e-9fb3-8928c6eb1189" xlink:to="loc_srt_ConsolidatedEntitiesDomain_66376269-a50c-4e0e-9fb3-8928c6eb1189_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_7acaa8ba-2b8f-41eb-9964-8e356afbfeda" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_66376269-a50c-4e0e-9fb3-8928c6eb1189" xlink:to="loc_srt_ConsolidatedEntitiesDomain_7acaa8ba-2b8f-41eb-9964-8e356afbfeda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMShanghaiMember_9c97e80d-8ebb-4a32-825a-d2ba2361df3a" xlink:href="acmr-20240331.xsd#acmr_ACMShanghaiMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7acaa8ba-2b8f-41eb-9964-8e356afbfeda" xlink:to="loc_acmr_ACMShanghaiMember_9c97e80d-8ebb-4a32-825a-d2ba2361df3a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract_4728db3f-326d-4aeb-bfce-79e74aedf8ba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_704a27ee-36d4-45a2-93f2-1755ac3fb518" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract_4728db3f-326d-4aeb-bfce-79e74aedf8ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CashCashEquivalentsAndRestrictedCashAndTimeDeposits_eb16cca6-6917-4f39-8b0a-3c9ca4dc9f0f" xlink:href="acmr-20240331.xsd#acmr_CashCashEquivalentsAndRestrictedCashAndTimeDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract_4728db3f-326d-4aeb-bfce-79e74aedf8ba" xlink:to="loc_acmr_CashCashEquivalentsAndRestrictedCashAndTimeDeposits_eb16cca6-6917-4f39-8b0a-3c9ca4dc9f0f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositAssets_138af40c-4812-4f3d-957a-3df3668cf3a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepositAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract_4728db3f-326d-4aeb-bfce-79e74aedf8ba" xlink:to="loc_us-gaap_DepositAssets_138af40c-4812-4f3d-957a-3df3668cf3a5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToSuppliersAndEmployees_03c877b0-fcc1-4ba1-afa9-67a792522c14" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToSuppliersAndEmployees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract_4728db3f-326d-4aeb-bfce-79e74aedf8ba" xlink:to="loc_us-gaap_PaymentsToSuppliersAndEmployees_03c877b0-fcc1-4ba1-afa9-67a792522c14" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSummaryofFairValueDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSummaryofFairValueDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSummaryofFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4aadd16c-4492-4d46-9133-d2cdf5f559b2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab03cb86-9b75-4991-807b-5bae0f9acd94" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4aadd16c-4492-4d46-9133-d2cdf5f559b2" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab03cb86-9b75-4991-807b-5bae0f9acd94" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_f08f642d-599d-4967-89b3-514c7b015e5b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab03cb86-9b75-4991-807b-5bae0f9acd94" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_f08f642d-599d-4967-89b3-514c7b015e5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_f08f642d-599d-4967-89b3-514c7b015e5b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_f08f642d-599d-4967-89b3-514c7b015e5b" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_f08f642d-599d-4967-89b3-514c7b015e5b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_71732082-0540-4a45-a173-ebcf09b0ff1c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_f08f642d-599d-4967-89b3-514c7b015e5b" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_71732082-0540-4a45-a173-ebcf09b0ff1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_6e2f5695-d546-42a5-bb85-eacf50cd4cf3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_71732082-0540-4a45-a173-ebcf09b0ff1c" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_6e2f5695-d546-42a5-bb85-eacf50cd4cf3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_670d417c-3887-4390-b978-0f23f1dc86de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_71732082-0540-4a45-a173-ebcf09b0ff1c" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_670d417c-3887-4390-b978-0f23f1dc86de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_c2fdf813-e36c-4161-9eb1-71ffdc37b231" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_71732082-0540-4a45-a173-ebcf09b0ff1c" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_c2fdf813-e36c-4161-9eb1-71ffdc37b231" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_d512a3b4-e8cc-4a5f-b17f-58ad5e0db18e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab03cb86-9b75-4991-807b-5bae0f9acd94" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_d512a3b4-e8cc-4a5f-b17f-58ad5e0db18e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_d512a3b4-e8cc-4a5f-b17f-58ad5e0db18e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_d512a3b4-e8cc-4a5f-b17f-58ad5e0db18e" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_d512a3b4-e8cc-4a5f-b17f-58ad5e0db18e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_daa23a58-2105-4f30-8a2b-b2ac08de8a08" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_d512a3b4-e8cc-4a5f-b17f-58ad5e0db18e" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_daa23a58-2105-4f30-8a2b-b2ac08de8a08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_2439b7ea-fc91-4c00-b363-04ded9eafc57" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_daa23a58-2105-4f30-8a2b-b2ac08de8a08" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_2439b7ea-fc91-4c00-b363-04ded9eafc57" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_3e7e8bc5-b268-4f36-a87f-24fb96621608" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsNonrecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_daa23a58-2105-4f30-8a2b-b2ac08de8a08" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_3e7e8bc5-b268-4f36-a87f-24fb96621608" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_268bdec1-dd7f-4b94-aa24-74ce2439e647" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4aadd16c-4492-4d46-9133-d2cdf5f559b2" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_268bdec1-dd7f-4b94-aa24-74ce2439e647" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_0222f8ad-85b4-44b3-b4b6-30b36b0cc937" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_268bdec1-dd7f-4b94-aa24-74ce2439e647" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_0222f8ad-85b4-44b3-b4b6-30b36b0cc937" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_a79c123b-765c-4c1f-8784-02ff89728b8b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_268bdec1-dd7f-4b94-aa24-74ce2439e647" xlink:to="loc_us-gaap_TradingSecurities_a79c123b-765c-4c1f-8784-02ff89728b8b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosure_b8991b3b-0495-4001-896d-6d7e188d198e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_268bdec1-dd7f-4b94-aa24-74ce2439e647" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosure_b8991b3b-0495-4001-896d-6d7e188d198e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_3bbf378e-8284-43f4-acdf-b2e989a9f086" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_268bdec1-dd7f-4b94-aa24-74ce2439e647" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_3bbf378e-8284-43f4-acdf-b2e989a9f086" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTimeDepositsDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTimeDepositsDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTimeDepositsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_acmr_DepositsAssetsLineItems_be2d0d4f-b44f-4749-9a41-a359ce8f9b20" xlink:href="acmr-20240331.xsd#acmr_DepositsAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_DepositsAssetsTable_eefedd89-9bda-45dd-aab3-564f07559a4f" xlink:href="acmr-20240331.xsd#acmr_DepositsAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_acmr_DepositsAssetsLineItems_be2d0d4f-b44f-4749-9a41-a359ce8f9b20" xlink:to="loc_acmr_DepositsAssetsTable_eefedd89-9bda-45dd-aab3-564f07559a4f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_02f8ea11-1d2d-4fb6-9226-dcac1c8280e9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_DepositsAssetsTable_eefedd89-9bda-45dd-aab3-564f07559a4f" xlink:to="loc_srt_CounterpartyNameAxis_02f8ea11-1d2d-4fb6-9226-dcac1c8280e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_02f8ea11-1d2d-4fb6-9226-dcac1c8280e9_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_02f8ea11-1d2d-4fb6-9226-dcac1c8280e9" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_02f8ea11-1d2d-4fb6-9226-dcac1c8280e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_02f8ea11-1d2d-4fb6-9226-dcac1c8280e9" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ChinaMerchantBankDepositsMaturingOnJanuary292023Member_e6472e2e-d528-4480-903c-f5b0004df9f4" xlink:href="acmr-20240331.xsd#acmr_ChinaMerchantBankDepositsMaturingOnJanuary292023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ChinaMerchantBankDepositsMaturingOnJanuary292023Member_e6472e2e-d528-4480-903c-f5b0004df9f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_BankOfNingboDepositMaturingOnFebruary172024Member_6da1f33d-23c9-45aa-a62c-896d9d7c9b2d" xlink:href="acmr-20240331.xsd#acmr_BankOfNingboDepositMaturingOnFebruary172024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_BankOfNingboDepositMaturingOnFebruary172024Member_6da1f33d-23c9-45aa-a62c-896d9d7c9b2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingOctober202025Member_dabe4578-12d6-44a4-a613-bf6549c5d32c" xlink:href="acmr-20240331.xsd#acmr_ShanghaiPudongDevelopmentBankDepositMaturingOctober202025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingOctober202025Member_dabe4578-12d6-44a4-a613-bf6549c5d32c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingNovember142025Member_f4e4efa9-6bee-4793-a006-ea2579970471" xlink:href="acmr-20240331.xsd#acmr_ShanghaiPudongDevelopmentBankDepositMaturingNovember142025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingNovember142025Member_f4e4efa9-6bee-4793-a006-ea2579970471" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingDecember82025Member_a1c6d318-9481-473c-a0e5-a8ad7f111712" xlink:href="acmr-20240331.xsd#acmr_ShanghaiPudongDevelopmentBankDepositMaturingDecember82025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingDecember82025Member_a1c6d318-9481-473c-a0e5-a8ad7f111712" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingOnDecember252025Member_1b304b41-7d5d-4997-9a56-2f44348caa1c" xlink:href="acmr-20240331.xsd#acmr_ShanghaiPudongDevelopmentBankDepositMaturingOnDecember252025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingOnDecember252025Member_1b304b41-7d5d-4997-9a56-2f44348caa1c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingDecember302025Member_6eafda75-a7f6-4fd4-b9a5-ca6ef5f740c7" xlink:href="acmr-20240331.xsd#acmr_ShanghaiPudongDevelopmentBankDepositMaturingDecember302025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ShanghaiPudongDevelopmentBankDepositMaturingDecember302025Member_6eafda75-a7f6-4fd4-b9a5-ca6ef5f740c7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ChinaIndustrialBankDepositMaturingJanuary32026Member_0d2f3d24-3e5e-4592-a530-4069e554afcc" xlink:href="acmr-20240331.xsd#acmr_ChinaIndustrialBankDepositMaturingJanuary32026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ChinaIndustrialBankDepositMaturingJanuary32026Member_0d2f3d24-3e5e-4592-a530-4069e554afcc" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ChinaEverbrightBankDepositMaturingDecember52024Member_56450aac-276f-4354-92ec-2497bc265182" xlink:href="acmr-20240331.xsd#acmr_ChinaEverbrightBankDepositMaturingDecember52024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ChinaEverbrightBankDepositMaturingDecember52024Member_56450aac-276f-4354-92ec-2497bc265182" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ChinaEverbrightBankDepositMaturingMay222024Member_a8f2ee33-3728-4926-a749-f6f9e11574f1" xlink:href="acmr-20240331.xsd#acmr_ChinaEverbrightBankDepositMaturingMay222024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ChinaEverbrightBankDepositMaturingMay222024Member_a8f2ee33-3728-4926-a749-f6f9e11574f1" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ChinaEverbrightBankDepositMaturingApril52024Member_8bef9207-6642-4cec-90ea-7a001ba5786c" xlink:href="acmr-20240331.xsd#acmr_ChinaEverbrightBankDepositMaturingApril52024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ChinaEverbrightBankDepositMaturingApril52024Member_8bef9207-6642-4cec-90ea-7a001ba5786c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ChinaMerchantBankLujiazuiBranchDepositMaturingMay272024Member_ca820f38-8cee-4389-82be-124173d4a34b" xlink:href="acmr-20240331.xsd#acmr_ChinaMerchantBankLujiazuiBranchDepositMaturingMay272024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ChinaMerchantBankLujiazuiBranchDepositMaturingMay272024Member_ca820f38-8cee-4389-82be-124173d4a34b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ChinaMerchantBankHuaihaiBranchDepositsMaturingMay272024Member_fc7b9c4c-136a-4862-b8ae-0b750f11f78a" xlink:href="acmr-20240331.xsd#acmr_ChinaMerchantBankHuaihaiBranchDepositsMaturingMay272024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_ChinaMerchantBankHuaihaiBranchDepositsMaturingMay272024Member_fc7b9c4c-136a-4862-b8ae-0b750f11f78a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_BankOfNingboDepositMaturingSeptember112024Member_7e39437a-0365-430b-bd2f-120ea6a45718" xlink:href="acmr-20240331.xsd#acmr_BankOfNingboDepositMaturingSeptember112024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fa235681-f924-43cb-b3ae-c36e7f37d87e" xlink:to="loc_acmr_BankOfNingboDepositMaturingSeptember112024Member_7e39437a-0365-430b-bd2f-120ea6a45718" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsAbstract_ce526187-c4c7-415a-9b34-87c35da50a23" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepositsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_DepositsAssetsLineItems_be2d0d4f-b44f-4749-9a41-a359ce8f9b20" xlink:to="loc_us-gaap_DepositsAbstract_ce526187-c4c7-415a-9b34-87c35da50a23" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_TimeDepositsInterestRate_73c0d426-bb54-4791-86de-134457efbaef" xlink:href="acmr-20240331.xsd#acmr_TimeDepositsInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositsAbstract_ce526187-c4c7-415a-9b34-87c35da50a23" xlink:to="loc_acmr_TimeDepositsInterestRate_73c0d426-bb54-4791-86de-134457efbaef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositAssets_8709167f-084e-4817-8955-6c179fbcf290" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepositAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositsAbstract_ce526187-c4c7-415a-9b34-87c35da50a23" xlink:to="loc_us-gaap_DepositAssets_8709167f-084e-4817-8955-6c179fbcf290" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_51c9cdfe-8131-45d0-b0fc-4d853854033d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeDepositsWithFinancialInstitutions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_DepositsAssetsLineItems_be2d0d4f-b44f-4749-9a41-a359ce8f9b20" xlink:to="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_51c9cdfe-8131-45d0-b0fc-4d853854033d" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESConcentrationofCreditRiskDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESConcentrationofCreditRiskDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESConcentrationofCreditRiskDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_7ca6bc10-bcaf-424e-b05e-89339091ba67" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_5a7c9391-414f-4958-8e5a-281c5ef69c20" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_7ca6bc10-bcaf-424e-b05e-89339091ba67" xlink:to="loc_us-gaap_ConcentrationRiskTable_5a7c9391-414f-4958-8e5a-281c5ef69c20" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_fe02f2d4-6b76-4562-ba9f-d358db646f2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_5a7c9391-414f-4958-8e5a-281c5ef69c20" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_fe02f2d4-6b76-4562-ba9f-d358db646f2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_fe02f2d4-6b76-4562-ba9f-d358db646f2b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_fe02f2d4-6b76-4562-ba9f-d358db646f2b" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_fe02f2d4-6b76-4562-ba9f-d358db646f2b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_08252f04-5b5c-43f3-af75-d38a6fe198fe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_fe02f2d4-6b76-4562-ba9f-d358db646f2b" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_08252f04-5b5c-43f3-af75-d38a6fe198fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_67cba3dc-bf18-43c7-b5a1-647841361f29" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_08252f04-5b5c-43f3-af75-d38a6fe198fe" xlink:to="loc_us-gaap_SalesRevenueNetMember_67cba3dc-bf18-43c7-b5a1-647841361f29" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_65dd8cde-4909-4f3b-85ce-3c687fa66d02" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_08252f04-5b5c-43f3-af75-d38a6fe198fe" xlink:to="loc_us-gaap_AccountsReceivableMember_65dd8cde-4909-4f3b-85ce-3c687fa66d02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_b723a416-da5e-4860-a400-87feb51dabb0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_5a7c9391-414f-4958-8e5a-281c5ef69c20" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_b723a416-da5e-4860-a400-87feb51dabb0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_b723a416-da5e-4860-a400-87feb51dabb0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_b723a416-da5e-4860-a400-87feb51dabb0" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_b723a416-da5e-4860-a400-87feb51dabb0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_17570f01-09e6-46ad-b2d7-081d3812242a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_b723a416-da5e-4860-a400-87feb51dabb0" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_17570f01-09e6-46ad-b2d7-081d3812242a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_260f0226-240e-49fc-9c45-02a7ac427b63" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_17570f01-09e6-46ad-b2d7-081d3812242a" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_260f0226-240e-49fc-9c45-02a7ac427b63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_9a8b225d-69e3-4999-bf6c-ea9bbd7d14e7" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_5a7c9391-414f-4958-8e5a-281c5ef69c20" xlink:to="loc_srt_MajorCustomersAxis_9a8b225d-69e3-4999-bf6c-ea9bbd7d14e7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_9a8b225d-69e3-4999-bf6c-ea9bbd7d14e7_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_9a8b225d-69e3-4999-bf6c-ea9bbd7d14e7" xlink:to="loc_srt_NameOfMajorCustomerDomain_9a8b225d-69e3-4999-bf6c-ea9bbd7d14e7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_fe810043-c1d1-4912-93b5-c33e032252a2" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_9a8b225d-69e3-4999-bf6c-ea9bbd7d14e7" xlink:to="loc_srt_NameOfMajorCustomerDomain_fe810043-c1d1-4912-93b5-c33e032252a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_TwoCustomersMember_cdbf091c-051d-4642-8fff-dc563acb38a2" xlink:href="acmr-20240331.xsd#acmr_TwoCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_fe810043-c1d1-4912-93b5-c33e032252a2" xlink:to="loc_acmr_TwoCustomersMember_cdbf091c-051d-4642-8fff-dc563acb38a2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_FourCustomersMember_280171de-b784-4504-9c6b-f48b30eb0b5a" xlink:href="acmr-20240331.xsd#acmr_FourCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_fe810043-c1d1-4912-93b5-c33e032252a2" xlink:to="loc_acmr_FourCustomersMember_280171de-b784-4504-9c6b-f48b30eb0b5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ConcentrationOfCreditRiskAbstract_f4b8dd74-8f6f-4c46-bb90-bfdb3cda6e72" xlink:href="acmr-20240331.xsd#acmr_ConcentrationOfCreditRiskAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_7ca6bc10-bcaf-424e-b05e-89339091ba67" xlink:to="loc_acmr_ConcentrationOfCreditRiskAbstract_f4b8dd74-8f6f-4c46-bb90-bfdb3cda6e72" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_618a698a-3416-4946-bf9a-b259eaf845d2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_ConcentrationOfCreditRiskAbstract_f4b8dd74-8f6f-4c46-bb90-bfdb3cda6e72" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_618a698a-3416-4946-bf9a-b259eaf845d2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/REVENUEFROMCONTRACTSWITHCUSTOMERSDisaggregatedRevenueDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#REVENUEFROMCONTRACTSWITHCUSTOMERSDisaggregatedRevenueDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/REVENUEFROMCONTRACTSWITHCUSTOMERSDisaggregatedRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_eee8761c-c036-400b-bd30-8b4e168177c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_411525de-d1ae-47b7-9c69-e7c1002dd19f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_eee8761c-c036-400b-bd30-8b4e168177c2" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_411525de-d1ae-47b7-9c69-e7c1002dd19f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_6a8575b7-2628-4b5a-a244-7cbfa59235b4" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_411525de-d1ae-47b7-9c69-e7c1002dd19f" xlink:to="loc_srt_ProductOrServiceAxis_6a8575b7-2628-4b5a-a244-7cbfa59235b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_6a8575b7-2628-4b5a-a244-7cbfa59235b4_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_6a8575b7-2628-4b5a-a244-7cbfa59235b4" xlink:to="loc_srt_ProductsAndServicesDomain_6a8575b7-2628-4b5a-a244-7cbfa59235b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_1e5a2307-d3b2-43c9-9862-9a918078f90b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_6a8575b7-2628-4b5a-a244-7cbfa59235b4" xlink:to="loc_srt_ProductsAndServicesDomain_1e5a2307-d3b2-43c9-9862-9a918078f90b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_TotalSingleWaferAndSemiCriticalCleaningEquipmentMember_251e24fa-2cc5-4651-a855-b2eae7da02cd" xlink:href="acmr-20240331.xsd#acmr_TotalSingleWaferAndSemiCriticalCleaningEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_1e5a2307-d3b2-43c9-9862-9a918078f90b" xlink:to="loc_acmr_TotalSingleWaferAndSemiCriticalCleaningEquipmentMember_251e24fa-2cc5-4651-a855-b2eae7da02cd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ECPFrontEndAndPackagingFurnaceAndOtherTechnologiesMember_8c25123b-bbaa-403d-9f48-4b01a3059d3e" xlink:href="acmr-20240331.xsd#acmr_ECPFrontEndAndPackagingFurnaceAndOtherTechnologiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_1e5a2307-d3b2-43c9-9862-9a918078f90b" xlink:to="loc_acmr_ECPFrontEndAndPackagingFurnaceAndOtherTechnologiesMember_8c25123b-bbaa-403d-9f48-4b01a3059d3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_AdvancedPackagingExcludeECPServicesSparesMember_1d1091d5-202a-4d9d-9e7d-0978645b3f74" xlink:href="acmr-20240331.xsd#acmr_AdvancedPackagingExcludeECPServicesSparesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_1e5a2307-d3b2-43c9-9862-9a918078f90b" xlink:to="loc_acmr_AdvancedPackagingExcludeECPServicesSparesMember_1d1091d5-202a-4d9d-9e7d-0978645b3f74" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_2d700507-06b9-4667-9940-96a9b1fd82aa" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_411525de-d1ae-47b7-9c69-e7c1002dd19f" xlink:to="loc_srt_StatementGeographicalAxis_2d700507-06b9-4667-9940-96a9b1fd82aa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_2d700507-06b9-4667-9940-96a9b1fd82aa_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_2d700507-06b9-4667-9940-96a9b1fd82aa" xlink:to="loc_srt_SegmentGeographicalDomain_2d700507-06b9-4667-9940-96a9b1fd82aa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_74d3dab9-73e7-4e4f-8a57-b611b2831709" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_2d700507-06b9-4667-9940-96a9b1fd82aa" xlink:to="loc_srt_SegmentGeographicalDomain_74d3dab9-73e7-4e4f-8a57-b611b2831709" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_5da40a9f-bfa7-4dda-93b6-a1938fdbab8e" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_74d3dab9-73e7-4e4f-8a57-b611b2831709" xlink:to="loc_country_CN_5da40a9f-bfa7-4dda-93b6-a1938fdbab8e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_OherRegionsMember_faeb1c1b-e703-4990-84e7-371d2d1591ae" xlink:href="acmr-20240331.xsd#acmr_OherRegionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_74d3dab9-73e7-4e4f-8a57-b611b2831709" xlink:to="loc_acmr_OherRegionsMember_faeb1c1b-e703-4990-84e7-371d2d1591ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_DisaggregatedRevenueInformationAbstract_5812c216-f044-4fee-94c2-b31a3b1275a7" xlink:href="acmr-20240331.xsd#acmr_DisaggregatedRevenueInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_eee8761c-c036-400b-bd30-8b4e168177c2" xlink:to="loc_acmr_DisaggregatedRevenueInformationAbstract_5812c216-f044-4fee-94c2-b31a3b1275a7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_356c60e5-5d74-4e31-941d-d52b92bf4e41" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_DisaggregatedRevenueInformationAbstract_5812c216-f044-4fee-94c2-b31a3b1275a7" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_356c60e5-5d74-4e31-941d-d52b92bf4e41" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/REVENUEFROMCONTRACTSWITHCUSTOMERSNarrativeDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#REVENUEFROMCONTRACTSWITHCUSTOMERSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/REVENUEFROMCONTRACTSWITHCUSTOMERSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_18f8d6b5-3ff1-483a-8cb9-9eb82b43719c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_bbdf4e93-5b12-4fa1-9def-76b63ee61cb2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_18f8d6b5-3ff1-483a-8cb9-9eb82b43719c" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_bbdf4e93-5b12-4fa1-9def-76b63ee61cb2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryAxis_017451c0-bab6-4270-b41c-90b43bde8529" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_bbdf4e93-5b12-4fa1-9def-76b63ee61cb2" xlink:to="loc_us-gaap_PublicUtilitiesInventoryAxis_017451c0-bab6-4270-b41c-90b43bde8529" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_017451c0-bab6-4270-b41c-90b43bde8529_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_017451c0-bab6-4270-b41c-90b43bde8529" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_017451c0-bab6-4270-b41c-90b43bde8529_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_38a3d92c-6944-461c-8d62-e55a1f36d286" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_017451c0-bab6-4270-b41c-90b43bde8529" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_38a3d92c-6944-461c-8d62-e55a1f36d286" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_FirstToolsMember_7ad20040-6bac-4c06-b985-3a139ee435cd" xlink:href="acmr-20240331.xsd#acmr_FirstToolsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_38a3d92c-6944-461c-8d62-e55a1f36d286" xlink:to="loc_acmr_FirstToolsMember_7ad20040-6bac-4c06-b985-3a139ee435cd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_d6913fe8-48f3-401c-b659-d4e21d3afe6f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_18f8d6b5-3ff1-483a-8cb9-9eb82b43719c" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_d6913fe8-48f3-401c-b659-d4e21d3afe6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_97a3cc7f-035d-434d-b1c4-0c77607d2d47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_18f8d6b5-3ff1-483a-8cb9-9eb82b43719c" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_97a3cc7f-035d-434d-b1c4-0c77607d2d47" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/ACCOUNTSRECEIVABLESummaryofAllowanceForDoubtfulAccountsDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#ACCOUNTSRECEIVABLESummaryofAllowanceForDoubtfulAccountsDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/ACCOUNTSRECEIVABLESummaryofAllowanceForDoubtfulAccountsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_639c49b9-9ddc-4f7e-9600-e0aa40f1776a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_9fb54cd0-d6df-4bfb-b8c9-da4e27349da6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_639c49b9-9ddc-4f7e-9600-e0aa40f1776a" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_9fb54cd0-d6df-4bfb-b8c9-da4e27349da6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_e476fc33-851d-4fcd-9380-04d588f2fc63" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_9fb54cd0-d6df-4bfb-b8c9-da4e27349da6" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_e476fc33-851d-4fcd-9380-04d588f2fc63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_e476fc33-851d-4fcd-9380-04d588f2fc63_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_e476fc33-851d-4fcd-9380-04d588f2fc63" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_e476fc33-851d-4fcd-9380-04d588f2fc63_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_b9221a91-2e6d-4458-9fe5-915f41be6f16" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_e476fc33-851d-4fcd-9380-04d588f2fc63" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_b9221a91-2e6d-4458-9fe5-915f41be6f16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_54d56536-def3-424e-a3f5-445d4aa93855" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_b9221a91-2e6d-4458-9fe5-915f41be6f16" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_54d56536-def3-424e-a3f5-445d4aa93855" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRollforward_853da9ef-45de-4461-a315-050c28681b10" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableRollforward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_639c49b9-9ddc-4f7e-9600-e0aa40f1776a" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRollforward_853da9ef-45de-4461-a315-050c28681b10" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_bbcc3b47-d93c-448f-9f08-16b875ed62a8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRollforward_853da9ef-45de-4461-a315-050c28681b10" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_bbcc3b47-d93c-448f-9f08-16b875ed62a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_AccountsReceivableCreditLossExpenseReversalIncludingForeignCurrencyExchangeRate_17e1d9c1-8bac-4819-b605-e02e9008ec63" xlink:href="acmr-20240331.xsd#acmr_AccountsReceivableCreditLossExpenseReversalIncludingForeignCurrencyExchangeRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRollforward_853da9ef-45de-4461-a315-050c28681b10" xlink:to="loc_acmr_AccountsReceivableCreditLossExpenseReversalIncludingForeignCurrencyExchangeRate_17e1d9c1-8bac-4819-b605-e02e9008ec63" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_346eff14-8ae0-440e-b00f-2c6725d2182d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/INVENTORIESDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#INVENTORIESDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/INVENTORIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryLineItems_2d7d9a4e-4ec6-4698-ab7a-eb1f4392278a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryCurrentTable_d9fb5dec-2cf3-49fe-9fb5-dbf4f20baba0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryCurrentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InventoryLineItems_2d7d9a4e-4ec6-4698-ab7a-eb1f4392278a" xlink:to="loc_us-gaap_InventoryCurrentTable_d9fb5dec-2cf3-49fe-9fb5-dbf4f20baba0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryAxis_580a5716-5fac-4c20-8eaf-bd8f7fda2cc1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_d9fb5dec-2cf3-49fe-9fb5-dbf4f20baba0" xlink:to="loc_us-gaap_PublicUtilitiesInventoryAxis_580a5716-5fac-4c20-8eaf-bd8f7fda2cc1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_580a5716-5fac-4c20-8eaf-bd8f7fda2cc1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_580a5716-5fac-4c20-8eaf-bd8f7fda2cc1" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_580a5716-5fac-4c20-8eaf-bd8f7fda2cc1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_a19a8ad1-09ee-404e-890a-03544076d0ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_580a5716-5fac-4c20-8eaf-bd8f7fda2cc1" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_a19a8ad1-09ee-404e-890a-03544076d0ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_FirstToolsMember_dc193a6d-1e56-4fda-b9ed-4cb8989b2197" xlink:href="acmr-20240331.xsd#acmr_FirstToolsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_a19a8ad1-09ee-404e-890a-03544076d0ff" xlink:to="loc_acmr_FirstToolsMember_dc193a6d-1e56-4fda-b9ed-4cb8989b2197" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_FirstToolsCustomerOwnershipMember_fa53555c-aeae-4a07-9d00-200be0c010e5" xlink:href="acmr-20240331.xsd#acmr_FirstToolsCustomerOwnershipMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_a19a8ad1-09ee-404e-890a-03544076d0ff" xlink:to="loc_acmr_FirstToolsCustomerOwnershipMember_fa53555c-aeae-4a07-9d00-200be0c010e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_2d7d9a4e-4ec6-4698-ab7a-eb1f4392278a" xlink:to="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryRawMaterials_84aa1b7c-d007-4f1a-a2b3-e0259487d906" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryRawMaterials"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:to="loc_us-gaap_InventoryRawMaterials_84aa1b7c-d007-4f1a-a2b3-e0259487d906" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWorkInProcess_59423d98-3a68-4880-82c9-bd964be507c1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryWorkInProcess"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:to="loc_us-gaap_InventoryWorkInProcess_59423d98-3a68-4880-82c9-bd964be507c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoods_a68195a7-574c-4bc0-a250-b2885d280a05" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryFinishedGoods"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:to="loc_us-gaap_InventoryFinishedGoods_a68195a7-574c-4bc0-a250-b2885d280a05" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryGross_1772810e-8c33-4530-af1b-00e1354ff764" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:to="loc_us-gaap_InventoryGross_1772810e-8c33-4530-af1b-00e1354ff764" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_IncreaseDecreaseInRawMaterialsAndWorkInProcessInventory_bf25d729-c2d8-48b3-a040-9d7262f22297" xlink:href="acmr-20240331.xsd#acmr_IncreaseDecreaseInRawMaterialsAndWorkInProcessInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:to="loc_acmr_IncreaseDecreaseInRawMaterialsAndWorkInProcessInventory_bf25d729-c2d8-48b3-a040-9d7262f22297" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_IncreaseDecreaseInFinishedGoodsInventory_a2ba7f5a-82ef-4fb9-bee7-5842e11fa1b9" xlink:href="acmr-20240331.xsd#acmr_IncreaseDecreaseInFinishedGoodsInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:to="loc_acmr_IncreaseDecreaseInFinishedGoodsInventory_a2ba7f5a-82ef-4fb9-bee7-5842e11fa1b9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_InventoryImpairmentPeriod_7efea81a-f141-4bfe-a60f-08d98045671f" xlink:href="acmr-20240331.xsd#acmr_InventoryImpairmentPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:to="loc_acmr_InventoryImpairmentPeriod_7efea81a-f141-4bfe-a60f-08d98045671f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWriteDown_451272f6-31ba-43b2-b004-3aac6092b5f9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryWriteDown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_b97f67e6-0dcf-42eb-8a12-d61c04e6a62b" xlink:to="loc_us-gaap_InventoryWriteDown_451272f6-31ba-43b2-b004-3aac6092b5f9" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/PROPERTYPLANTANDEQUIPMENTNETDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#PROPERTYPLANTANDEQUIPMENTNETDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/PROPERTYPLANTANDEQUIPMENTNETDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_79a247aa-93a8-4b28-9705-dad975751b95" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_2bf05c17-2f9b-487a-8dc5-7c19f5e796a4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_79a247aa-93a8-4b28-9705-dad975751b95" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_2bf05c17-2f9b-487a-8dc5-7c19f5e796a4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_21d1086d-d8e0-465c-8804-89300a21529a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_2bf05c17-2f9b-487a-8dc5-7c19f5e796a4" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_21d1086d-d8e0-465c-8804-89300a21529a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_21d1086d-d8e0-465c-8804-89300a21529a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_21d1086d-d8e0-465c-8804-89300a21529a" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_21d1086d-d8e0-465c-8804-89300a21529a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d6433311-b585-45f4-8e2e-984183fecf7c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_21d1086d-d8e0-465c-8804-89300a21529a" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d6433311-b585-45f4-8e2e-984183fecf7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_BuildingsAndPlantsMember_cca1ea62-7953-489d-a6e9-993b76dbd88c" xlink:href="acmr-20240331.xsd#acmr_BuildingsAndPlantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d6433311-b585-45f4-8e2e-984183fecf7c" xlink:to="loc_acmr_BuildingsAndPlantsMember_cca1ea62-7953-489d-a6e9-993b76dbd88c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquipmentMember_f639281e-4ef0-4aab-b96b-a6b170f8679e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d6433311-b585-45f4-8e2e-984183fecf7c" xlink:to="loc_us-gaap_EquipmentMember_f639281e-4ef0-4aab-b96b-a6b170f8679e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OfficeEquipmentMember_ea17a256-df12-415b-a1f3-4ade02b61aff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OfficeEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d6433311-b585-45f4-8e2e-984183fecf7c" xlink:to="loc_us-gaap_OfficeEquipmentMember_ea17a256-df12-415b-a1f3-4ade02b61aff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransportationEquipmentMember_322abeda-66c2-4f8d-8c06-fc6d3959b84b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransportationEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d6433311-b585-45f4-8e2e-984183fecf7c" xlink:to="loc_us-gaap_TransportationEquipmentMember_322abeda-66c2-4f8d-8c06-fc6d3959b84b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_010a1e31-8c0b-4c82-a0d9-7c284f61a8dd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d6433311-b585-45f4-8e2e-984183fecf7c" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_010a1e31-8c0b-4c82-a0d9-7c284f61a8dd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_ac5df566-c27a-4a16-b344-8611e66999b6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_2bf05c17-2f9b-487a-8dc5-7c19f5e796a4" xlink:to="loc_srt_ConsolidatedEntitiesAxis_ac5df566-c27a-4a16-b344-8611e66999b6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_ac5df566-c27a-4a16-b344-8611e66999b6_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_ac5df566-c27a-4a16-b344-8611e66999b6" xlink:to="loc_srt_ConsolidatedEntitiesDomain_ac5df566-c27a-4a16-b344-8611e66999b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_a53f3dc8-d2fb-4b97-85b6-e225bdbb2468" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_ac5df566-c27a-4a16-b344-8611e66999b6" xlink:to="loc_srt_ConsolidatedEntitiesDomain_a53f3dc8-d2fb-4b97-85b6-e225bdbb2468" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMLingangMember_c8d45a34-8bba-4d7c-b908-9886357e8adf" xlink:href="acmr-20240331.xsd#acmr_ACMLingangMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_a53f3dc8-d2fb-4b97-85b6-e225bdbb2468" xlink:to="loc_acmr_ACMLingangMember_c8d45a34-8bba-4d7c-b908-9886357e8adf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMShanghaiMember_930621e8-3223-4af5-a8bc-b1878231e3ee" xlink:href="acmr-20240331.xsd#acmr_ACMShanghaiMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_a53f3dc8-d2fb-4b97-85b6-e225bdbb2468" xlink:to="loc_acmr_ACMShanghaiMember_930621e8-3223-4af5-a8bc-b1878231e3ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_0381bfd2-09a9-4296-9c77-3c77cb44605c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_79a247aa-93a8-4b28-9705-dad975751b95" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_0381bfd2-09a9-4296-9c77-3c77cb44605c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_e262bacf-f5d4-4150-be0e-0cbe893648be" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_0381bfd2-09a9-4296-9c77-3c77cb44605c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_e262bacf-f5d4-4150-be0e-0cbe893648be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_0cac0e0c-2d79-4a92-9c6a-9fc746ecb415" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_0381bfd2-09a9-4296-9c77-3c77cb44605c" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_0cac0e0c-2d79-4a92-9c6a-9fc746ecb415" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressGross_b21a4877-6c68-431b-9627-bc02f66a7dcc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConstructionInProgressGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_0381bfd2-09a9-4296-9c77-3c77cb44605c" xlink:to="loc_us-gaap_ConstructionInProgressGross_b21a4877-6c68-431b-9627-bc02f66a7dcc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_40d4d3f5-7906-4eea-8fe7-d9b3e422cb07" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_0381bfd2-09a9-4296-9c77-3c77cb44605c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_40d4d3f5-7906-4eea-8fe7-d9b3e422cb07" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_4e03861d-b94f-4eb7-9227-07ec5af03ad6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_0381bfd2-09a9-4296-9c77-3c77cb44605c" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_4e03861d-b94f-4eb7-9227-07ec5af03ad6" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/OTHERLONGTERMASSETSNarrativeDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#OTHERLONGTERMASSETSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/OTHERLONGTERMASSETSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_f9af210d-8e58-47f4-a27c-1df777a9b377" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_e0f332a0-6fde-4f12-817a-f5a13de8ff0d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_f9af210d-8e58-47f4-a27c-1df777a9b377" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_e0f332a0-6fde-4f12-817a-f5a13de8ff0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_853fe410-212a-405d-bf55-4629aea1571e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_e0f332a0-6fde-4f12-817a-f5a13de8ff0d" xlink:to="loc_srt_ConsolidatedEntitiesAxis_853fe410-212a-405d-bf55-4629aea1571e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_853fe410-212a-405d-bf55-4629aea1571e_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_853fe410-212a-405d-bf55-4629aea1571e" xlink:to="loc_srt_ConsolidatedEntitiesDomain_853fe410-212a-405d-bf55-4629aea1571e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_f81b489e-a62b-4b3c-80ee-42daed3c9ef1" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_853fe410-212a-405d-bf55-4629aea1571e" xlink:to="loc_srt_ConsolidatedEntitiesDomain_f81b489e-a62b-4b3c-80ee-42daed3c9ef1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShengweiResearchShanghaiIncMember_b99fe9dc-df18-4436-bbd6-d6564e0634e2" xlink:href="acmr-20240331.xsd#acmr_ShengweiResearchShanghaiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_f81b489e-a62b-4b3c-80ee-42daed3c9ef1" xlink:to="loc_acmr_ShengweiResearchShanghaiIncMember_b99fe9dc-df18-4436-bbd6-d6564e0634e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_98b99a8c-da98-49ba-9e36-40a399cef5e2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_e0f332a0-6fde-4f12-817a-f5a13de8ff0d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_98b99a8c-da98-49ba-9e36-40a399cef5e2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_98b99a8c-da98-49ba-9e36-40a399cef5e2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_98b99a8c-da98-49ba-9e36-40a399cef5e2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_98b99a8c-da98-49ba-9e36-40a399cef5e2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_68e3412f-6543-43ed-9bab-2ad629d93758" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_98b99a8c-da98-49ba-9e36-40a399cef5e2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_68e3412f-6543-43ed-9bab-2ad629d93758" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_BuildingsAndPlantsMember_e3c62874-6352-4e96-949f-fd75d9d1b0ef" xlink:href="acmr-20240331.xsd#acmr_BuildingsAndPlantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_68e3412f-6543-43ed-9bab-2ad629d93758" xlink:to="loc_acmr_BuildingsAndPlantsMember_e3c62874-6352-4e96-949f-fd75d9d1b0ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_a2e09246-d859-4608-8b32-2da72c819f49" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_f9af210d-8e58-47f4-a27c-1df777a9b377" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_a2e09246-d859-4608-8b32-2da72c819f49" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/SHORTTERMBORROWINGSDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#SHORTTERMBORROWINGSDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/SHORTTERMBORROWINGSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtLineItems_de193714-064c-4f8d-8b1e-8cd0ea53e142" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermDebtLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShortTermDebtTable_c94683e5-8910-4e56-ae83-27b7ea8a63d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShortTermDebtTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShortTermDebtLineItems_de193714-064c-4f8d-8b1e-8cd0ea53e142" xlink:to="loc_us-gaap_ScheduleOfShortTermDebtTable_c94683e5-8910-4e56-ae83-27b7ea8a63d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_0a522b1b-78de-4303-9c91-2c21df575a23" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShortTermDebtTable_c94683e5-8910-4e56-ae83-27b7ea8a63d3" xlink:to="loc_us-gaap_DebtInstrumentAxis_0a522b1b-78de-4303-9c91-2c21df575a23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_0a522b1b-78de-4303-9c91-2c21df575a23_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_0a522b1b-78de-4303-9c91-2c21df575a23" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_0a522b1b-78de-4303-9c91-2c21df575a23_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4b6753aa-ce2c-4752-94a5-2dcd8715edcd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_0a522b1b-78de-4303-9c91-2c21df575a23" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4b6753aa-ce2c-4752-94a5-2dcd8715edcd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditUpToRMB150000FromChinaEverbrightBankMember_5171ffe2-a54d-4650-9fc9-814071d86893" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditUpToRMB150000FromChinaEverbrightBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4b6753aa-ce2c-4752-94a5-2dcd8715edcd" xlink:to="loc_acmr_LineOfCreditUpToRMB150000FromChinaEverbrightBankMember_5171ffe2-a54d-4650-9fc9-814071d86893" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditDueOnAugust292024WithAnAnnualInterestRateOf3.00Member_1d1162e6-daad-4d72-890c-e35bc396eeff" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditDueOnAugust292024WithAnAnnualInterestRateOf3.00Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB150000FromChinaEverbrightBankMember_5171ffe2-a54d-4650-9fc9-814071d86893" xlink:to="loc_acmr_LineOfCreditDueOnAugust292024WithAnAnnualInterestRateOf3.00Member_1d1162e6-daad-4d72-890c-e35bc396eeff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditUpToRMB40000FromBankOfChinaMember_e7eba763-4416-4617-b1de-6b8e610c3121" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditUpToRMB40000FromBankOfChinaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4b6753aa-ce2c-4752-94a5-2dcd8715edcd" xlink:to="loc_acmr_LineOfCreditUpToRMB40000FromBankOfChinaMember_e7eba763-4416-4617-b1de-6b8e610c3121" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditDueOnSeptember72024WithAnAnnualInterestRateOf2.87.Member_e41e8241-9004-427a-9bb1-c8659cb5d751" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditDueOnSeptember72024WithAnAnnualInterestRateOf2.87.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB40000FromBankOfChinaMember_e7eba763-4416-4617-b1de-6b8e610c3121" xlink:to="loc_acmr_LineOfCreditDueOnSeptember72024WithAnAnnualInterestRateOf2.87.Member_e41e8241-9004-427a-9bb1-c8659cb5d751" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4b6753aa-ce2c-4752-94a5-2dcd8715edcd" xlink:to="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust72024WithAnAnnualInterestRateOf300Member_5fced0bb-63cc-42be-b575-6db24c4b799f" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust72024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust72024WithAnAnnualInterestRateOf300Member_5fced0bb-63cc-42be-b575-6db24c4b799f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust82024WithAnAnnualInterestRateOf300Member_395eca63-0437-4fe8-919f-39cded3ab440" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust82024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust82024WithAnAnnualInterestRateOf300Member_395eca63-0437-4fe8-919f-39cded3ab440" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust92024WithAnAnnualInterestRateOf300Member_28d48308-1709-42d4-8f6e-4d82143a7393" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust92024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust92024WithAnAnnualInterestRateOf300Member_28d48308-1709-42d4-8f6e-4d82143a7393" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust142024WithAnAnnualInterestRateOf300Member_947f3a35-2665-4095-8270-9c59a81f8f38" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust142024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust142024WithAnAnnualInterestRateOf300Member_947f3a35-2665-4095-8270-9c59a81f8f38" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust172024WithAnAnnualInterestRateOf300Member_32cbc886-f166-4773-ba20-1aed87059508" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust172024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust172024WithAnAnnualInterestRateOf300Member_32cbc886-f166-4773-ba20-1aed87059508" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust202024WithAnAnnualInterestRateOf300Member_4e6ed3fc-3a0a-4b97-97a6-c98973ad27d1" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust202024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust202024WithAnAnnualInterestRateOf300Member_4e6ed3fc-3a0a-4b97-97a6-c98973ad27d1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust212024WithAnAnnualInterestRateOf300Member_feb8db62-d000-4dbb-b5e5-9969106270c6" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust212024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust212024WithAnAnnualInterestRateOf300Member_feb8db62-d000-4dbb-b5e5-9969106270c6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust222024WithAnAnnualInterestRateOf300Member_09395954-cad7-449b-a646-a54f9dae0f8d" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust222024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust222024WithAnAnnualInterestRateOf300Member_09395954-cad7-449b-a646-a54f9dae0f8d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust242024WithAnAnnualInterestRateOf300Member_121bf130-33bd-4784-adef-2d8fb8f18390" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust242024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust242024WithAnAnnualInterestRateOf300Member_121bf130-33bd-4784-adef-2d8fb8f18390" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust272024WithAnAnnualInterestRateOf300Member_c39f17d5-a2b2-43e1-8108-11ea7aeaca02" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust272024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust272024WithAnAnnualInterestRateOf300Member_c39f17d5-a2b2-43e1-8108-11ea7aeaca02" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust292024WithAnAnnualInterestRateOf300Member_31ce5905-3630-4bca-854f-cf4fd45a3707" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust292024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust292024WithAnAnnualInterestRateOf300Member_31ce5905-3630-4bca-854f-cf4fd45a3707" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust302024WithAnAnnualInterestRateOf300Member_b463245d-818a-42b3-a055-9b9ef1df1e46" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnAugust302024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnAugust302024WithAnAnnualInterestRateOf300Member_b463245d-818a-42b3-a055-9b9ef1df1e46" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember32024WithAnAnnualInterestRateOf300Member_6a8acae7-f8af-4dff-a093-28fa40277caa" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnSeptember32024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember32024WithAnAnnualInterestRateOf300Member_6a8acae7-f8af-4dff-a093-28fa40277caa" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember52024WithAnAnnualInterestRateOf300Member_b1a91e9b-f2a2-4e39-b5ad-b5fc09e7780f" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnSeptember52024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember52024WithAnAnnualInterestRateOf300Member_b1a91e9b-f2a2-4e39-b5ad-b5fc09e7780f" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember62024WithAnAnnualInterestRateOf300Member_cddbb5f4-47ae-4f6c-af4e-bce71a9060e0" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnSeptember62024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember62024WithAnAnnualInterestRateOf300Member_cddbb5f4-47ae-4f6c-af4e-bce71a9060e0" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember102024WithAnAnnualInterestRateOf300Member_e64f6178-6d91-40eb-ad79-54e062220fc3" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnSeptember102024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember102024WithAnAnnualInterestRateOf300Member_e64f6178-6d91-40eb-ad79-54e062220fc3" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember122024WithAnAnnualInterestRateOf300Member_c82b1d8c-1664-45eb-b17d-04e97576583d" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnSeptember122024WithAnAnnualInterestRateOf300Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnSeptember122024WithAnAnnualInterestRateOf300Member_c82b1d8c-1664-45eb-b17d-04e97576583d" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnFebruary272025WithAnAnnualInterestRateOf2.60Member_e4f221b7-37ca-4223-9d19-703e3881ac2d" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnFebruary272025WithAnAnnualInterestRateOf2.60Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnFebruary272025WithAnAnnualInterestRateOf2.60Member_e4f221b7-37ca-4223-9d19-703e3881ac2d" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnFebruary282025WithAnAnnualInterestRateOf2.60Member_2700aff0-e3be-4b6e-b71c-ea8a74f987a6" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnFebruary282025WithAnAnnualInterestRateOf2.60Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnFebruary282025WithAnAnnualInterestRateOf2.60Member_2700aff0-e3be-4b6e-b71c-ea8a74f987a6" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnMarch12025WithAnAnnualInterestRateOf2.60Member_1751b56e-bf28-42f7-a230-f558111cd3ea" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnMarch12025WithAnAnnualInterestRateOf2.60Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnMarch12025WithAnAnnualInterestRateOf2.60Member_1751b56e-bf28-42f7-a230-f558111cd3ea" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnMarch52025WithAnAnnualInterestRateOf2.60Member_81cea12a-2dbc-42ea-bde6-36dc253dd1f4" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnMarch52025WithAnAnnualInterestRateOf2.60Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnMarch52025WithAnAnnualInterestRateOf2.60Member_81cea12a-2dbc-42ea-bde6-36dc253dd1f4" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditChinaMerchantsBankDueOnMarch82025WithAnAnnualInterestRateOf2.60Member_87b19837-b1fd-4dfe-a6d4-348dc5061290" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditChinaMerchantsBankDueOnMarch82025WithAnAnnualInterestRateOf2.60Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB200000FromChinaMerchantsBankMember_e865cf02-d9be-4317-8365-2116dc0c03b5" xlink:to="loc_acmr_LineOfCreditChinaMerchantsBankDueOnMarch82025WithAnAnnualInterestRateOf2.60Member_87b19837-b1fd-4dfe-a6d4-348dc5061290" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditUpToRMB120000FromBankOfChinaMember_070cde6b-df0b-448f-8ef7-3c2745b23f2f" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditUpToRMB120000FromBankOfChinaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4b6753aa-ce2c-4752-94a5-2dcd8715edcd" xlink:to="loc_acmr_LineOfCreditUpToRMB120000FromBankOfChinaMember_070cde6b-df0b-448f-8ef7-3c2745b23f2f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditBankOfChinaDueOnMarch202025WithAnAnnualInterestRateOf2.75Member_180a60c7-1a78-4c83-aaef-3c83ca8fc57a" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditBankOfChinaDueOnMarch202025WithAnAnnualInterestRateOf2.75Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToRMB120000FromBankOfChinaMember_070cde6b-df0b-448f-8ef7-3c2745b23f2f" xlink:to="loc_acmr_LineOfCreditBankOfChinaDueOnMarch202025WithAnAnnualInterestRateOf2.75Member_180a60c7-1a78-4c83-aaef-3c83ca8fc57a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditUpToKRW500000FromIndustrialBankOfKoreaMember_1080c2dd-7600-4f43-a9ca-798f0d8c7370" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditUpToKRW500000FromIndustrialBankOfKoreaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4b6753aa-ce2c-4752-94a5-2dcd8715edcd" xlink:to="loc_acmr_LineOfCreditUpToKRW500000FromIndustrialBankOfKoreaMember_1080c2dd-7600-4f43-a9ca-798f0d8c7370" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditDueOnJuly122024WithAnAnnualInterestRateOf6.03Member_c61878dd-ae00-4861-a3a7-45195e29ab45" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditDueOnJuly122024WithAnAnnualInterestRateOf6.03Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToKRW500000FromIndustrialBankOfKoreaMember_1080c2dd-7600-4f43-a9ca-798f0d8c7370" xlink:to="loc_acmr_LineOfCreditDueOnJuly122024WithAnAnnualInterestRateOf6.03Member_c61878dd-ae00-4861-a3a7-45195e29ab45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditUpToKRW2000000FromIndustrialBankOfKoreaMember_a53a33b3-bba1-415d-97ba-5c3d4e070c89" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditUpToKRW2000000FromIndustrialBankOfKoreaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4b6753aa-ce2c-4752-94a5-2dcd8715edcd" xlink:to="loc_acmr_LineOfCreditUpToKRW2000000FromIndustrialBankOfKoreaMember_a53a33b3-bba1-415d-97ba-5c3d4e070c89" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LineOfCreditDueOnDecember152024WithAnAnnualInterestRateOf4.29Member_87119da5-e446-4e38-96cb-162b8ed50a73" xlink:href="acmr-20240331.xsd#acmr_LineOfCreditDueOnDecember152024WithAnAnnualInterestRateOf4.29Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LineOfCreditUpToKRW2000000FromIndustrialBankOfKoreaMember_a53a33b3-bba1-415d-97ba-5c3d4e070c89" xlink:to="loc_acmr_LineOfCreditDueOnDecember152024WithAnAnnualInterestRateOf4.29Member_87119da5-e446-4e38-96cb-162b8ed50a73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowingsAbstract_20e3b86d-d511-4a0d-9e35-d2a90517932b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermBorrowingsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtLineItems_de193714-064c-4f8d-8b1e-8cd0ea53e142" xlink:to="loc_us-gaap_ShortTermBorrowingsAbstract_20e3b86d-d511-4a0d-9e35-d2a90517932b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7e3cfb85-a1b9-4d94-9ee2-3e4d5a4456ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermBorrowingsAbstract_20e3b86d-d511-4a0d-9e35-d2a90517932b" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7e3cfb85-a1b9-4d94-9ee2-3e4d5a4456ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_8e220c7d-93a2-401a-a928-ea6b5948338a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityInterestRateDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermBorrowingsAbstract_20e3b86d-d511-4a0d-9e35-d2a90517932b" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_8e220c7d-93a2-401a-a928-ea6b5948338a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_407fc41a-90c3-4342-b47a-4560513b92dc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermBorrowingsAbstract_20e3b86d-d511-4a0d-9e35-d2a90517932b" xlink:to="loc_us-gaap_ShortTermBorrowings_407fc41a-90c3-4342-b47a-4560513b92dc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseShortTermBorrowings_d8604145-d3df-48de-98df-e2e866fac108" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpenseShortTermBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtLineItems_de193714-064c-4f8d-8b1e-8cd0ea53e142" xlink:to="loc_us-gaap_InterestExpenseShortTermBorrowings_d8604145-d3df-48de-98df-e2e866fac108" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/LONGTERMBORROWINGSSummaryofLongtermBorrowingsDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#LONGTERMBORROWINGSSummaryofLongtermBorrowingsDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/LONGTERMBORROWINGSSummaryofLongtermBorrowingsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_19366d39-5062-4831-91be-30caeff9b158" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_d4cce62f-65e6-4ab4-887b-8304f1d1361b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_19366d39-5062-4831-91be-30caeff9b158" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_d4cce62f-65e6-4ab4-887b-8304f1d1361b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis_d66c4292-f74a-4273-b313-ada25abb48f7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_d4cce62f-65e6-4ab4-887b-8304f1d1361b" xlink:to="loc_us-gaap_LineOfCreditFacilityAxis_d66c4292-f74a-4273-b313-ada25abb48f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_d66c4292-f74a-4273-b313-ada25abb48f7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_d66c4292-f74a-4273-b313-ada25abb48f7" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_d66c4292-f74a-4273-b313-ada25abb48f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_a482af6b-6c6d-4954-b0ab-4972b116b590" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_d66c4292-f74a-4273-b313-ada25abb48f7" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_a482af6b-6c6d-4954-b0ab-4972b116b590" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ChinaMerchantsBankMember_da1eb3fe-8d63-4a9d-9743-cf594bf42799" xlink:href="acmr-20240331.xsd#acmr_ChinaMerchantsBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_a482af6b-6c6d-4954-b0ab-4972b116b590" xlink:to="loc_acmr_ChinaMerchantsBankMember_da1eb3fe-8d63-4a9d-9743-cf594bf42799" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_BankOfChinaMember_382ba542-040d-4e16-8618-c0a916251420" xlink:href="acmr-20240331.xsd#acmr_BankOfChinaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_a482af6b-6c6d-4954-b0ab-4972b116b590" xlink:to="loc_acmr_BankOfChinaMember_382ba542-040d-4e16-8618-c0a916251420" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_BankOfShanghaiMember_dbeb75e9-2b26-4a95-acbf-61a914b36369" xlink:href="acmr-20240331.xsd#acmr_BankOfShanghaiMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_a482af6b-6c6d-4954-b0ab-4972b116b590" xlink:to="loc_acmr_BankOfShanghaiMember_dbeb75e9-2b26-4a95-acbf-61a914b36369" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CiticBankMember_f13954a1-958d-4092-b3a1-0543749a615e" xlink:href="acmr-20240331.xsd#acmr_CiticBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_a482af6b-6c6d-4954-b0ab-4972b116b590" xlink:to="loc_acmr_CiticBankMember_f13954a1-958d-4092-b3a1-0543749a615e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_9b5c1c72-6857-4306-9a85-ba8902746471" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_d4cce62f-65e6-4ab4-887b-8304f1d1361b" xlink:to="loc_us-gaap_DebtInstrumentAxis_9b5c1c72-6857-4306-9a85-ba8902746471" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_9b5c1c72-6857-4306-9a85-ba8902746471_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_9b5c1c72-6857-4306-9a85-ba8902746471" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_9b5c1c72-6857-4306-9a85-ba8902746471_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_aeb4f224-2ac0-4009-85fb-6110c095741e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_9b5c1c72-6857-4306-9a85-ba8902746471" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_aeb4f224-2ac0-4009-85fb-6110c095741e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LoneOneMember_07f10313-be5e-4b95-9da6-7aaa868181b6" xlink:href="acmr-20240331.xsd#acmr_LoneOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_aeb4f224-2ac0-4009-85fb-6110c095741e" xlink:to="loc_acmr_LoneOneMember_07f10313-be5e-4b95-9da6-7aaa868181b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LoanTwoMember_90664953-9a1f-4936-a654-9824dc7784b7" xlink:href="acmr-20240331.xsd#acmr_LoanTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_aeb4f224-2ac0-4009-85fb-6110c095741e" xlink:to="loc_acmr_LoanTwoMember_90664953-9a1f-4936-a654-9824dc7784b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_02c80bbc-8e51-4e96-8b74-fed75b078878" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtCurrentAndNoncurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_19366d39-5062-4831-91be-30caeff9b158" xlink:to="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_02c80bbc-8e51-4e96-8b74-fed75b078878" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_f45b057c-9724-4339-976b-9f3328ac830f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_02c80bbc-8e51-4e96-8b74-fed75b078878" xlink:to="loc_us-gaap_LongTermDebt_f45b057c-9724-4339-976b-9f3328ac830f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_0aa94a2a-5f3d-48c0-8404-360addff7aed" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_02c80bbc-8e51-4e96-8b74-fed75b078878" xlink:to="loc_us-gaap_LongTermDebtCurrent_0aa94a2a-5f3d-48c0-8404-360addff7aed" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_c09efee9-f96a-4882-b8b2-7c8b533525ba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_02c80bbc-8e51-4e96-8b74-fed75b078878" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_c09efee9-f96a-4882-b8b2-7c8b533525ba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_NumberOfInstallmentsForLoanRepayable_aa554139-5f18-4615-831c-19a1152f23c5" xlink:href="acmr-20240331.xsd#acmr_NumberOfInstallmentsForLoanRepayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_19366d39-5062-4831-91be-30caeff9b158" xlink:to="loc_acmr_NumberOfInstallmentsForLoanRepayable_aa554139-5f18-4615-831c-19a1152f23c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_e9731e10-5d07-4dd0-a076-b0dee95257fc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityInterestRateDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_19366d39-5062-4831-91be-30caeff9b158" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_e9731e10-5d07-4dd0-a076-b0dee95257fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_NumberOfLoans_d525380e-69c2-4227-9b8e-c6bd689245ad" xlink:href="acmr-20240331.xsd#acmr_NumberOfLoans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_19366d39-5062-4831-91be-30caeff9b158" xlink:to="loc_acmr_NumberOfLoans_d525380e-69c2-4227-9b8e-c6bd689245ad" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_cf02470e-d66e-436c-9196-1098a7d3686a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebt"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_1e345ef2-6226-4f67-8b82-7f9443b07159" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_19366d39-5062-4831-91be-30caeff9b158" xlink:to="loc_us-gaap_LongTermDebtFairValue_1e345ef2-6226-4f67-8b82-7f9443b07159" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestCostsIncurred_616bc996-b707-43ee-8cd4-3129d731efce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestCostsIncurred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_19366d39-5062-4831-91be-30caeff9b158" xlink:to="loc_us-gaap_InterestCostsIncurred_616bc996-b707-43ee-8cd4-3129d731efce" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/OTHERLONGTERMLIABILITIESDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#OTHERLONGTERMLIABILITIESDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/OTHERLONGTERMLIABILITIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_69798a65-d702-443c-b7da-90567f8af956" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_0ff7e80e-e125-4a99-849f-5106a18c0510" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_69798a65-d702-443c-b7da-90567f8af956" xlink:to="loc_us-gaap_DebtInstrumentTable_0ff7e80e-e125-4a99-849f-5106a18c0510" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_e2480f21-76fa-4ee5-a3d4-8e5236e163dc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_0ff7e80e-e125-4a99-849f-5106a18c0510" xlink:to="loc_us-gaap_DebtInstrumentAxis_e2480f21-76fa-4ee5-a3d4-8e5236e163dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_e2480f21-76fa-4ee5-a3d4-8e5236e163dc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_e2480f21-76fa-4ee5-a3d4-8e5236e163dc" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_e2480f21-76fa-4ee5-a3d4-8e5236e163dc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_6e84c93c-86d0-4456-914a-6bf43dc692b6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_e2480f21-76fa-4ee5-a3d4-8e5236e163dc" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_6e84c93c-86d0-4456-914a-6bf43dc692b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_SubsidiesToStressFreePolishingProjectMember_eaadf185-c81e-49cd-ba8e-557d2b084506" xlink:href="acmr-20240331.xsd#acmr_SubsidiesToStressFreePolishingProjectMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6e84c93c-86d0-4456-914a-6bf43dc692b6" xlink:to="loc_acmr_SubsidiesToStressFreePolishingProjectMember_eaadf185-c81e-49cd-ba8e-557d2b084506" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_SubsidiesToElectroCopperPlatingProjectMember_7b0a0cf0-52e3-4b8a-9bd1-c353959c906c" xlink:href="acmr-20240331.xsd#acmr_SubsidiesToElectroCopperPlatingProjectMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6e84c93c-86d0-4456-914a-6bf43dc692b6" xlink:to="loc_acmr_SubsidiesToElectroCopperPlatingProjectMember_7b0a0cf0-52e3-4b8a-9bd1-c353959c906c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_SubsidiesToSWLingangRDDevelopmentIn2021Member_90ce58da-0378-41af-a45a-6bcde7db755a" xlink:href="acmr-20240331.xsd#acmr_SubsidiesToSWLingangRDDevelopmentIn2021Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6e84c93c-86d0-4456-914a-6bf43dc692b6" xlink:to="loc_acmr_SubsidiesToSWLingangRDDevelopmentIn2021Member_90ce58da-0378-41af-a45a-6bcde7db755a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_OtherMember_c8d5c547-bb46-4305-b256-959abf476bfe" xlink:href="acmr-20240331.xsd#acmr_OtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6e84c93c-86d0-4456-914a-6bf43dc692b6" xlink:to="loc_acmr_OtherMember_c8d5c547-bb46-4305-b256-959abf476bfe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_0ff0e49a-7df5-477e-8ab3-30f642f4beb2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesNoncurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_69798a65-d702-443c-b7da-90567f8af956" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_0ff0e49a-7df5-477e-8ab3-30f642f4beb2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_ac4596af-4b35-4c12-a9b5-0fd02b6ef12a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_0ff0e49a-7df5-477e-8ab3-30f642f4beb2" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_ac4596af-4b35-4c12-a9b5-0fd02b6ef12a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/LONGTERMINVESTMENTNarrativeDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#LONGTERMINVESTMENTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/LONGTERMINVESTMENTNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LongTermInvestmentLineItems_06e44d6c-5db5-483e-9c9d-326af2681b23" xlink:href="acmr-20240331.xsd#acmr_LongTermInvestmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LongTermInvestmentsTable_23a79d13-d6f8-4278-82ce-96eb91ea913c" xlink:href="acmr-20240331.xsd#acmr_LongTermInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_acmr_LongTermInvestmentLineItems_06e44d6c-5db5-483e-9c9d-326af2681b23" xlink:to="loc_acmr_LongTermInvestmentsTable_23a79d13-d6f8-4278-82ce-96eb91ea913c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c22fe6a2-e931-4157-b04d-99ea29c3a6a9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_LongTermInvestmentsTable_23a79d13-d6f8-4278-82ce-96eb91ea913c" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c22fe6a2-e931-4157-b04d-99ea29c3a6a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_c22fe6a2-e931-4157-b04d-99ea29c3a6a9_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c22fe6a2-e931-4157-b04d-99ea29c3a6a9" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_c22fe6a2-e931-4157-b04d-99ea29c3a6a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_8941fe50-7fcb-4b4c-9d10-8084553633c0" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c22fe6a2-e931-4157-b04d-99ea29c3a6a9" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_8941fe50-7fcb-4b4c-9d10-8084553633c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_EquityInvestmentMember_9b2c8a87-eb12-4d48-8d65-be00807278af" xlink:href="acmr-20240331.xsd#acmr_EquityInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_8941fe50-7fcb-4b4c-9d10-8084553633c0" xlink:to="loc_acmr_EquityInvestmentMember_9b2c8a87-eb12-4d48-8d65-be00807278af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_2f8e6c66-62b1-4da0-9ca4-e276057f7a02" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_LongTermInvestmentsTable_23a79d13-d6f8-4278-82ce-96eb91ea913c" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_2f8e6c66-62b1-4da0-9ca4-e276057f7a02" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_2f8e6c66-62b1-4da0-9ca4-e276057f7a02_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_2f8e6c66-62b1-4da0-9ca4-e276057f7a02" xlink:to="loc_us-gaap_RelatedPartyDomain_2f8e6c66-62b1-4da0-9ca4-e276057f7a02_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_2f8e6c66-62b1-4da0-9ca4-e276057f7a02" xlink:to="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_NinebellCompanyLimitedMember_28f296c5-3f4a-46e2-a96f-ef2e06ee54b3" xlink:href="acmr-20240331.xsd#acmr_NinebellCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_NinebellCompanyLimitedMember_28f296c5-3f4a-46e2-a96f-ef2e06ee54b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_WooilFluconCompanyLimitedMember_eb735811-0e16-4268-befb-65c52d307539" xlink:href="acmr-20240331.xsd#acmr_WooilFluconCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_WooilFluconCompanyLimitedMember_eb735811-0e16-4268-befb-65c52d307539" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_HefeiShixiChanhengIntegratedCircuitIndustryVentureCapitalFundPartnershipMember_461f18e8-bc0a-4031-ab86-9dd8490ca458" xlink:href="acmr-20240331.xsd#acmr_HefeiShixiChanhengIntegratedCircuitIndustryVentureCapitalFundPartnershipMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_HefeiShixiChanhengIntegratedCircuitIndustryVentureCapitalFundPartnershipMember_461f18e8-bc0a-4031-ab86-9dd8490ca458" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShengyiSemiconductorTechnologyCompanyLimitedMember_738a0155-7fc7-4e9a-a887-8c80b50226b5" xlink:href="acmr-20240331.xsd#acmr_ShengyiSemiconductorTechnologyCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_ShengyiSemiconductorTechnologyCompanyLimitedMember_738a0155-7fc7-4e9a-a887-8c80b50226b5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CompanyDMember_9a9640a2-b8c1-40c0-8a09-7f95c0cda4be" xlink:href="acmr-20240331.xsd#acmr_CompanyDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_CompanyDMember_9a9640a2-b8c1-40c0-8a09-7f95c0cda4be" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CompanyAMember_fa3e58c4-7479-447b-a533-b10b0e16b39d" xlink:href="acmr-20240331.xsd#acmr_CompanyAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_CompanyAMember_fa3e58c4-7479-447b-a533-b10b0e16b39d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CompanyBMember_f5289516-4598-426a-b65f-c7a31f745ec7" xlink:href="acmr-20240331.xsd#acmr_CompanyBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_CompanyBMember_f5289516-4598-426a-b65f-c7a31f745ec7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CompanyCMember_43fa8bc9-ebd1-4c51-8688-db1fd4f3e75f" xlink:href="acmr-20240331.xsd#acmr_CompanyCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_CompanyCMember_43fa8bc9-ebd1-4c51-8688-db1fd4f3e75f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_WaferworksCompanyLimitedMember_bc0dd2de-d965-4b1b-9d6d-ec81428d3b4d" xlink:href="acmr-20240331.xsd#acmr_WaferworksCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_WaferworksCompanyLimitedMember_bc0dd2de-d965-4b1b-9d6d-ec81428d3b4d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShengyiMember_c2cb9010-bc50-4dae-ad6f-46e896dce95d" xlink:href="acmr-20240331.xsd#acmr_ShengyiMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_f45c712a-ad5f-4ff6-90f3-fad85b588977" xlink:to="loc_acmr_ShengyiMember_c2cb9010-bc50-4dae-ad6f-46e896dce95d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_75f71f2a-fbc8-498f-88ea-7805a487b991" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_LongTermInvestmentsTable_23a79d13-d6f8-4278-82ce-96eb91ea913c" xlink:to="loc_us-gaap_StatementClassOfStockAxis_75f71f2a-fbc8-498f-88ea-7805a487b991" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_75f71f2a-fbc8-498f-88ea-7805a487b991_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_75f71f2a-fbc8-498f-88ea-7805a487b991" xlink:to="loc_us-gaap_ClassOfStockDomain_75f71f2a-fbc8-498f-88ea-7805a487b991_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_680ad9be-1f1c-4b2c-b2c0-54f7629141c9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_75f71f2a-fbc8-498f-88ea-7805a487b991" xlink:to="loc_us-gaap_ClassOfStockDomain_680ad9be-1f1c-4b2c-b2c0-54f7629141c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_8a8ed911-e6fa-4c3d-99b5-9fcadc675548" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_680ad9be-1f1c-4b2c-b2c0-54f7629141c9" xlink:to="loc_us-gaap_CommonClassAMember_8a8ed911-e6fa-4c3d-99b5-9fcadc675548" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsAbstract_ac5e4886-b664-4cdd-a10a-74a2c323e089" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LongTermInvestmentLineItems_06e44d6c-5db5-483e-9c9d-326af2681b23" xlink:to="loc_us-gaap_InvestmentsAbstract_ac5e4886-b664-4cdd-a10a-74a2c323e089" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_d625bf3e-f7bd-4a16-a8c4-016c2467d95b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_ac5e4886-b664-4cdd-a10a-74a2c323e089" xlink:to="loc_us-gaap_EquityMethodInvestments_d625bf3e-f7bd-4a16-a8c4-016c2467d95b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_0836d1a3-6be5-4f25-8921-67e650a4cab7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_ac5e4886-b664-4cdd-a10a-74a2c323e089" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_0836d1a3-6be5-4f25-8921-67e650a4cab7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_13f179ff-191a-4cc3-a493-5bc2c74543e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_ac5e4886-b664-4cdd-a10a-74a2c323e089" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_13f179ff-191a-4cc3-a493-5bc2c74543e3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_167860e0-ccca-4042-b1a9-2098737deee9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_ac5e4886-b664-4cdd-a10a-74a2c323e089" xlink:to="loc_us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_167860e0-ccca-4042-b1a9-2098737deee9" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/LONGTERMINVESTMENTSummaryofLongTermInvestmentsDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#LONGTERMINVESTMENTSummaryofLongTermInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/LONGTERMINVESTMENTSummaryofLongTermInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LongTermInvestmentsLineItems_4dfff4aa-89d0-4de2-9ecf-36f11bce9e90" xlink:href="acmr-20240331.xsd#acmr_LongTermInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LongTermInvestmentsTable_2091247c-dbe8-4f35-a6e6-163f5b9d5833" xlink:href="acmr-20240331.xsd#acmr_LongTermInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_acmr_LongTermInvestmentsLineItems_4dfff4aa-89d0-4de2-9ecf-36f11bce9e90" xlink:to="loc_acmr_LongTermInvestmentsTable_2091247c-dbe8-4f35-a6e6-163f5b9d5833" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_01359a43-cd48-485e-ae96-d9e9f7cfbe1b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_LongTermInvestmentsTable_2091247c-dbe8-4f35-a6e6-163f5b9d5833" xlink:to="loc_us-gaap_InvestmentTypeAxis_01359a43-cd48-485e-ae96-d9e9f7cfbe1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_01359a43-cd48-485e-ae96-d9e9f7cfbe1b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_01359a43-cd48-485e-ae96-d9e9f7cfbe1b" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_01359a43-cd48-485e-ae96-d9e9f7cfbe1b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_0c7a4348-53ef-4f7f-b513-54cbc9796c38" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_01359a43-cd48-485e-ae96-d9e9f7cfbe1b" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_0c7a4348-53ef-4f7f-b513-54cbc9796c38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_InvestmentExcludingOtherMember_ad9c0dda-57e8-4b1c-a3bc-7a84e93e1d4c" xlink:href="acmr-20240331.xsd#acmr_InvestmentExcludingOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_0c7a4348-53ef-4f7f-b513-54cbc9796c38" xlink:to="loc_acmr_InvestmentExcludingOtherMember_ad9c0dda-57e8-4b1c-a3bc-7a84e93e1d4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLongTermInvestmentsMember_a5fc5610-1a1e-410c-8dc2-f2eede64a3f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLongTermInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_0c7a4348-53ef-4f7f-b513-54cbc9796c38" xlink:to="loc_us-gaap_OtherLongTermInvestmentsMember_a5fc5610-1a1e-410c-8dc2-f2eede64a3f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_34fd3da4-0012-4b31-8a9c-68ee97169bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_LongTermInvestmentsTable_2091247c-dbe8-4f35-a6e6-163f5b9d5833" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_34fd3da4-0012-4b31-8a9c-68ee97169bbd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_34fd3da4-0012-4b31-8a9c-68ee97169bbd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_34fd3da4-0012-4b31-8a9c-68ee97169bbd" xlink:to="loc_us-gaap_RelatedPartyDomain_34fd3da4-0012-4b31-8a9c-68ee97169bbd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_34fd3da4-0012-4b31-8a9c-68ee97169bbd" xlink:to="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_NinebellCompanyLimitedMember_c23c9d66-7e7f-4bf7-9d47-a4f8cec617a3" xlink:href="acmr-20240331.xsd#acmr_NinebellCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_NinebellCompanyLimitedMember_c23c9d66-7e7f-4bf7-9d47-a4f8cec617a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_WooilFluconCompanyLimitedMember_b9b50768-4102-4015-bd70-67a612dafdff" xlink:href="acmr-20240331.xsd#acmr_WooilFluconCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_WooilFluconCompanyLimitedMember_b9b50768-4102-4015-bd70-67a612dafdff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShengyiSemiconductorTechnologyCompanyLimitedMember_43e661d9-c17b-40ca-8618-c9a42b71d24e" xlink:href="acmr-20240331.xsd#acmr_ShengyiSemiconductorTechnologyCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_ShengyiSemiconductorTechnologyCompanyLimitedMember_43e661d9-c17b-40ca-8618-c9a42b71d24e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_HefeiShixiChanhengIntegratedCircuitIndustryVentureCapitalFundPartnershipMember_87a97667-7b8e-45ef-a3a0-aff32e975dcf" xlink:href="acmr-20240331.xsd#acmr_HefeiShixiChanhengIntegratedCircuitIndustryVentureCapitalFundPartnershipMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_HefeiShixiChanhengIntegratedCircuitIndustryVentureCapitalFundPartnershipMember_87a97667-7b8e-45ef-a3a0-aff32e975dcf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_WaferworksCompanyLimitedMember_3110e6e1-9f2f-41ab-913a-a7dd1a49f57d" xlink:href="acmr-20240331.xsd#acmr_WaferworksCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_WaferworksCompanyLimitedMember_3110e6e1-9f2f-41ab-913a-a7dd1a49f57d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CompanyAMember_edf3e6de-1f61-4efd-871b-063b92392a19" xlink:href="acmr-20240331.xsd#acmr_CompanyAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_CompanyAMember_edf3e6de-1f61-4efd-871b-063b92392a19" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CompanyBMember_7c503f5f-f5d2-4e4d-9bb5-49c73b31f19d" xlink:href="acmr-20240331.xsd#acmr_CompanyBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_CompanyBMember_7c503f5f-f5d2-4e4d-9bb5-49c73b31f19d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CompanyCMember_08b53740-37e6-4d9f-a659-c1318a143857" xlink:href="acmr-20240331.xsd#acmr_CompanyCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_CompanyCMember_08b53740-37e6-4d9f-a659-c1318a143857" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_CompanyDMember_88e7e41d-eb67-4bf2-93a3-8c9ca16bf1d7" xlink:href="acmr-20240331.xsd#acmr_CompanyDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_CompanyDMember_88e7e41d-eb67-4bf2-93a3-8c9ca16bf1d7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_OtherMember_aeaa8123-e79c-4c6e-b527-0887df81bc28" xlink:href="acmr-20240331.xsd#acmr_OtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c5235cbd-5727-4c2b-8b5c-9592930e31e9" xlink:to="loc_acmr_OtherMember_aeaa8123-e79c-4c6e-b527-0887df81bc28" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_d8db7e81-1bb7-4819-8e1c-1fe14d3e00ce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_LongTermInvestmentsLineItems_4dfff4aa-89d0-4de2-9ecf-36f11bce9e90" xlink:to="loc_us-gaap_LongTermInvestments_d8db7e81-1bb7-4819-8e1c-1fe14d3e00ce" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/SHORTTERMINVESTMENTSNarrativeDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#SHORTTERMINVESTMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/SHORTTERMINVESTMENTSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_88b309d9-f6d7-424d-9f3c-9cbfcaeb57a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_edf97eaa-dcd6-42f6-939f-94d72d53ea3e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_88b309d9-f6d7-424d-9f3c-9cbfcaeb57a9" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_edf97eaa-dcd6-42f6-939f-94d72d53ea3e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_0957c431-515c-4a75-82ef-9da145ac351f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_edf97eaa-dcd6-42f6-939f-94d72d53ea3e" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_0957c431-515c-4a75-82ef-9da145ac351f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_0957c431-515c-4a75-82ef-9da145ac351f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_0957c431-515c-4a75-82ef-9da145ac351f" xlink:to="loc_us-gaap_RelatedPartyDomain_0957c431-515c-4a75-82ef-9da145ac351f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_dbcb2138-9f4e-4b60-80e2-06c721bdde87" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_0957c431-515c-4a75-82ef-9da145ac351f" xlink:to="loc_us-gaap_RelatedPartyDomain_dbcb2138-9f4e-4b60-80e2-06c721bdde87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_NuodeAssetManagementCompanyLimitedMember_6efb735d-eed0-4f61-8934-cc7f3e38167a" xlink:href="acmr-20240331.xsd#acmr_NuodeAssetManagementCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_dbcb2138-9f4e-4b60-80e2-06c721bdde87" xlink:to="loc_acmr_NuodeAssetManagementCompanyLimitedMember_6efb735d-eed0-4f61-8934-cc7f3e38167a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_SemiconductorManufacturingInternationalCorporationMember_3b10e645-c997-48d8-92bf-00393979bad0" xlink:href="acmr-20240331.xsd#acmr_SemiconductorManufacturingInternationalCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_dbcb2138-9f4e-4b60-80e2-06c721bdde87" xlink:to="loc_acmr_SemiconductorManufacturingInternationalCorporationMember_3b10e645-c997-48d8-92bf-00393979bad0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_HuahongSemiconductorLimitedMember_97edbe3c-32ba-431f-a1ab-1b87ed4e7bb7" xlink:href="acmr-20240331.xsd#acmr_HuahongSemiconductorLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_dbcb2138-9f4e-4b60-80e2-06c721bdde87" xlink:to="loc_acmr_HuahongSemiconductorLimitedMember_97edbe3c-32ba-431f-a1ab-1b87ed4e7bb7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ZhongiuxinLimitedCompanyMember_f4480f44-f600-4e76-bfbe-70f2c43bc6fb" xlink:href="acmr-20240331.xsd#acmr_ZhongiuxinLimitedCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_dbcb2138-9f4e-4b60-80e2-06c721bdde87" xlink:to="loc_acmr_ZhongiuxinLimitedCompanyMember_f4480f44-f600-4e76-bfbe-70f2c43bc6fb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShanghaiSyncrystallineSiliconMaterialsCo.LtdMember_36039687-5de7-47ae-aaa9-e40d08854932" xlink:href="acmr-20240331.xsd#acmr_ShanghaiSyncrystallineSiliconMaterialsCo.LtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_dbcb2138-9f4e-4b60-80e2-06c721bdde87" xlink:to="loc_acmr_ShanghaiSyncrystallineSiliconMaterialsCo.LtdMember_36039687-5de7-47ae-aaa9-e40d08854932" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_c65a486c-26ec-45e8-a397-f8a2d096c346" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_edf97eaa-dcd6-42f6-939f-94d72d53ea3e" xlink:to="loc_srt_RangeAxis_c65a486c-26ec-45e8-a397-f8a2d096c346" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_c65a486c-26ec-45e8-a397-f8a2d096c346_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_c65a486c-26ec-45e8-a397-f8a2d096c346" xlink:to="loc_srt_RangeMember_c65a486c-26ec-45e8-a397-f8a2d096c346_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_39f79c89-34aa-4792-94f3-21b53a09db91" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_c65a486c-26ec-45e8-a397-f8a2d096c346" xlink:to="loc_srt_RangeMember_39f79c89-34aa-4792-94f3-21b53a09db91" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_225b6ed3-b680-43a1-98ee-a7374420bf15" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_39f79c89-34aa-4792-94f3-21b53a09db91" xlink:to="loc_srt_MinimumMember_225b6ed3-b680-43a1-98ee-a7374420bf15" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsAbstract_1f015b30-4aeb-4374-9829-38756fa9bb91" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_88b309d9-f6d7-424d-9f3c-9cbfcaeb57a9" xlink:to="loc_us-gaap_InvestmentsAbstract_1f015b30-4aeb-4374-9829-38756fa9bb91" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_InvestmentInPartnership_7f79be4f-c1e9-4737-adf3-1f9ceff8e841" xlink:href="acmr-20240331.xsd#acmr_InvestmentInPartnership"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_1f015b30-4aeb-4374-9829-38756fa9bb91" xlink:to="loc_acmr_InvestmentInPartnership_7f79be4f-c1e9-4737-adf3-1f9ceff8e841" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_OwnershipPercentageInPartnership_550bb888-1031-47ce-9baa-2f6c74e02584" xlink:href="acmr-20240331.xsd#acmr_OwnershipPercentageInPartnership"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_1f015b30-4aeb-4374-9829-38756fa9bb91" xlink:to="loc_acmr_OwnershipPercentageInPartnership_550bb888-1031-47ce-9baa-2f6c74e02584" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_79e57e59-be6b-4121-9d0d-630cb04dd978" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_1f015b30-4aeb-4374-9829-38756fa9bb91" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_79e57e59-be6b-4121-9d0d-630cb04dd978" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_DebtSecuritiesSaleOfShortTermInvestmentsReceivable_7b655a84-af0f-4a23-ac7e-1f7f634715eb" xlink:href="acmr-20240331.xsd#acmr_DebtSecuritiesSaleOfShortTermInvestmentsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_1f015b30-4aeb-4374-9829-38756fa9bb91" xlink:to="loc_acmr_DebtSecuritiesSaleOfShortTermInvestmentsReceivable_7b655a84-af0f-4a23-ac7e-1f7f634715eb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments_dac5dcf2-92a0-424b-a6b1-6d82f5d98f29" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsAbstract_1f015b30-4aeb-4374-9829-38756fa9bb91" xlink:to="loc_us-gaap_MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments_dac5dcf2-92a0-424b-a6b1-6d82f5d98f29" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/RELATEDPARTYBALANCESANDTRANSACTIONSDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#RELATEDPARTYBALANCESANDTRANSACTIONSDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/RELATEDPARTYBALANCESANDTRANSACTIONSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_ff76e5a6-322b-45fa-8792-27ac6830eaaf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_9187a979-760f-4360-8f1f-ce7d4a9e5b98" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_ff76e5a6-322b-45fa-8792-27ac6830eaaf" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_9187a979-760f-4360-8f1f-ce7d4a9e5b98" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_eb3611bf-9b09-4011-babb-fb8a82345d42" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_9187a979-760f-4360-8f1f-ce7d4a9e5b98" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_eb3611bf-9b09-4011-babb-fb8a82345d42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_eb3611bf-9b09-4011-babb-fb8a82345d42_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_eb3611bf-9b09-4011-babb-fb8a82345d42" xlink:to="loc_us-gaap_RelatedPartyDomain_eb3611bf-9b09-4011-babb-fb8a82345d42_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_5c66d72f-e142-41d6-88fa-18c92a73144f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_eb3611bf-9b09-4011-babb-fb8a82345d42" xlink:to="loc_us-gaap_RelatedPartyDomain_5c66d72f-e142-41d6-88fa-18c92a73144f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_c3a84b18-e6e3-4094-8277-e50b96a458f1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_5c66d72f-e142-41d6-88fa-18c92a73144f" xlink:to="loc_us-gaap_RelatedPartyMember_c3a84b18-e6e3-4094-8277-e50b96a458f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_fb187db1-4afd-4ef7-9aea-5deb7b44706f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_9187a979-760f-4360-8f1f-ce7d4a9e5b98" xlink:to="loc_srt_CounterpartyNameAxis_fb187db1-4afd-4ef7-9aea-5deb7b44706f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fb187db1-4afd-4ef7-9aea-5deb7b44706f_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_fb187db1-4afd-4ef7-9aea-5deb7b44706f" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fb187db1-4afd-4ef7-9aea-5deb7b44706f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_5bc24b89-5fc4-44cc-b41b-ae329135de55" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_fb187db1-4afd-4ef7-9aea-5deb7b44706f" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_5bc24b89-5fc4-44cc-b41b-ae329135de55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_NinebellCoLtdMember_7ee82cce-aacd-41ba-91e4-cae1d39b531b" xlink:href="acmr-20240331.xsd#acmr_NinebellCoLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_5bc24b89-5fc4-44cc-b41b-ae329135de55" xlink:to="loc_acmr_NinebellCoLtdMember_7ee82cce-aacd-41ba-91e4-cae1d39b531b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShengyiSemiconductorTechnologyCoLtdMember_5824f7ca-9b12-42d6-800e-2a40a48a6b8b" xlink:href="acmr-20240331.xsd#acmr_ShengyiSemiconductorTechnologyCoLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_5bc24b89-5fc4-44cc-b41b-ae329135de55" xlink:to="loc_acmr_ShengyiSemiconductorTechnologyCoLtdMember_5824f7ca-9b12-42d6-800e-2a40a48a6b8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty_72478340-7d83-47fd-ba81-a6be75c17c26" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_ff76e5a6-322b-45fa-8792-27ac6830eaaf" xlink:to="loc_us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty_72478340-7d83-47fd-ba81-a6be75c17c26" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherReceivablesNetCurrent_234ca6b2-e5b2-46f2-b684-10a4858e65b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherReceivablesNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_ff76e5a6-322b-45fa-8792-27ac6830eaaf" xlink:to="loc_us-gaap_OtherReceivablesNetCurrent_234ca6b2-e5b2-46f2-b684-10a4858e65b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_25ec875a-d8ff-468a-b9d9-e5a4c8b35bcd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_ff76e5a6-322b-45fa-8792-27ac6830eaaf" xlink:to="loc_us-gaap_AccountsPayableCurrent_25ec875a-d8ff-468a-b9d9-e5a4c8b35bcd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_0a7526a2-9fc5-42e9-b923-64a606c18928" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_ff76e5a6-322b-45fa-8792-27ac6830eaaf" xlink:to="loc_us-gaap_CostOfRevenue_0a7526a2-9fc5-42e9-b923-64a606c18928" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/COMMONSTOCKDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#COMMONSTOCKDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/COMMONSTOCKDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_bea9cc76-e14d-44ab-aa11-a64be57448cd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_c1ab43f4-f587-4920-a92e-9739a8399c83" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_bea9cc76-e14d-44ab-aa11-a64be57448cd" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_c1ab43f4-f587-4920-a92e-9739a8399c83" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_c5c0d715-9774-4123-9dcf-e01c9b69cd1e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_c1ab43f4-f587-4920-a92e-9739a8399c83" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_c5c0d715-9774-4123-9dcf-e01c9b69cd1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_c5c0d715-9774-4123-9dcf-e01c9b69cd1e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_c5c0d715-9774-4123-9dcf-e01c9b69cd1e" xlink:to="loc_us-gaap_EquityComponentDomain_c5c0d715-9774-4123-9dcf-e01c9b69cd1e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_abadf783-1da2-4919-9a2c-34f609563341" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_c5c0d715-9774-4123-9dcf-e01c9b69cd1e" xlink:to="loc_us-gaap_EquityComponentDomain_abadf783-1da2-4919-9a2c-34f609563341" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_f0b31346-0411-42c4-8eda-2647fcdad375" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_abadf783-1da2-4919-9a2c-34f609563341" xlink:to="loc_us-gaap_CommonStockMember_f0b31346-0411-42c4-8eda-2647fcdad375" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_f67fedca-de92-46a4-850b-171658b7d5ae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_c1ab43f4-f587-4920-a92e-9739a8399c83" xlink:to="loc_us-gaap_StatementClassOfStockAxis_f67fedca-de92-46a4-850b-171658b7d5ae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_f67fedca-de92-46a4-850b-171658b7d5ae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_f67fedca-de92-46a4-850b-171658b7d5ae" xlink:to="loc_us-gaap_ClassOfStockDomain_f67fedca-de92-46a4-850b-171658b7d5ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_a01fd9a4-068c-4b32-a9f3-5defc297a977" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_f67fedca-de92-46a4-850b-171658b7d5ae" xlink:to="loc_us-gaap_ClassOfStockDomain_a01fd9a4-068c-4b32-a9f3-5defc297a977" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_94ca90db-c6f6-42ab-be3d-2fb5501e2127" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_a01fd9a4-068c-4b32-a9f3-5defc297a977" xlink:to="loc_us-gaap_CommonClassAMember_94ca90db-c6f6-42ab-be3d-2fb5501e2127" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_f02f41c1-29f2-4ac4-9f91-3f4ed24f48bc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_a01fd9a4-068c-4b32-a9f3-5defc297a977" xlink:to="loc_us-gaap_CommonClassBMember_f02f41c1-29f2-4ac4-9f91-3f4ed24f48bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_bea9cc76-e14d-44ab-aa11-a64be57448cd" xlink:to="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_ec89f78f-fd39-4e63-b660-63281437c5b8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_ec89f78f-fd39-4e63-b660-63281437c5b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_53f95c03-c3b2-436f-b4a8-0f926cdf63f4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_53f95c03-c3b2-436f-b4a8-0f926cdf63f4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_VotingRightsPerShare_55b6857f-33fd-45cf-8484-442d7059ea75" xlink:href="acmr-20240331.xsd#acmr_VotingRightsPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:to="loc_acmr_VotingRightsPerShare_55b6857f-33fd-45cf-8484-442d7059ea75" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockSharesConverted1_a4b68deb-419a-4fd3-bc33-9b22b4035541" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockSharesConverted1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:to="loc_us-gaap_ConversionOfStockSharesConverted1_a4b68deb-419a-4fd3-bc33-9b22b4035541" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_f8d78353-f65a-41a8-b1aa-20550d97fa04" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_f8d78353-f65a-41a8-b1aa-20550d97fa04" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_e552f222-527f-4363-8882-7ae8f24ceb9d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:to="loc_us-gaap_CommonStockSharesIssued_e552f222-527f-4363-8882-7ae8f24ceb9d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_c19c2bbc-df68-4d77-8f22-35689c7f680e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDisclosuresAbstract_87938d0d-b901-4540-9f5c-ebef8e5c4143" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_c19c2bbc-df68-4d77-8f22-35689c7f680e" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/STOCKBASEDCOMPENSATIONShareOptionActivitiesDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#STOCKBASEDCOMPENSATIONShareOptionActivitiesDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/STOCKBASEDCOMPENSATIONShareOptionActivitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8a092cf6-97d6-4325-b74a-d4ee66decc02" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8a092cf6-97d6-4325-b74a-d4ee66decc02" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_462218e5-9fce-48e5-b5ea-bc8366db396b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8a092cf6-97d6-4325-b74a-d4ee66decc02" xlink:to="loc_us-gaap_AwardTypeAxis_462218e5-9fce-48e5-b5ea-bc8366db396b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_462218e5-9fce-48e5-b5ea-bc8366db396b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_462218e5-9fce-48e5-b5ea-bc8366db396b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_462218e5-9fce-48e5-b5ea-bc8366db396b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1ecfa234-310a-4a32-aa5d-d3ec08d26c29" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_462218e5-9fce-48e5-b5ea-bc8366db396b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1ecfa234-310a-4a32-aa5d-d3ec08d26c29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_914ee06f-b1d1-47c5-9567-3e5e8d26a5c1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1ecfa234-310a-4a32-aa5d-d3ec08d26c29" xlink:to="loc_us-gaap_EmployeeStockOptionMember_914ee06f-b1d1-47c5-9567-3e5e8d26a5c1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember_bf2c8437-3202-43f9-a8b4-7535f0fb60f7" xlink:href="acmr-20240331.xsd#acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1ecfa234-310a-4a32-aa5d-d3ec08d26c29" xlink:to="loc_acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember_bf2c8437-3202-43f9-a8b4-7535f0fb60f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_11209284-8cdb-465e-af1b-0f5aed974084" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8a092cf6-97d6-4325-b74a-d4ee66decc02" xlink:to="loc_srt_ConsolidatedEntitiesAxis_11209284-8cdb-465e-af1b-0f5aed974084" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_11209284-8cdb-465e-af1b-0f5aed974084_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_11209284-8cdb-465e-af1b-0f5aed974084" xlink:to="loc_srt_ConsolidatedEntitiesDomain_11209284-8cdb-465e-af1b-0f5aed974084_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_faf8f021-d160-4c98-95c2-fe834da3a807" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_11209284-8cdb-465e-af1b-0f5aed974084" xlink:to="loc_srt_ConsolidatedEntitiesDomain_faf8f021-d160-4c98-95c2-fe834da3a807" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchShanghaiIncMember_97e15e54-3709-4bb4-a8ce-2281ccbe36f2" xlink:href="acmr-20240331.xsd#acmr_ACMResearchShanghaiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_faf8f021-d160-4c98-95c2-fe834da3a807" xlink:to="loc_acmr_ACMResearchShanghaiIncMember_97e15e54-3709-4bb4-a8ce-2281ccbe36f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_aa5a11f6-478f-47b1-91dd-1cc0d961f9c3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8a092cf6-97d6-4325-b74a-d4ee66decc02" xlink:to="loc_us-gaap_PlanNameAxis_aa5a11f6-478f-47b1-91dd-1cc0d961f9c3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_aa5a11f6-478f-47b1-91dd-1cc0d961f9c3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_aa5a11f6-478f-47b1-91dd-1cc0d961f9c3" xlink:to="loc_us-gaap_PlanNameDomain_aa5a11f6-478f-47b1-91dd-1cc0d961f9c3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_e0d81a31-a043-4821-9ff1-3668bae34f49" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_aa5a11f6-478f-47b1-91dd-1cc0d961f9c3" xlink:to="loc_us-gaap_PlanNameDomain_e0d81a31-a043-4821-9ff1-3668bae34f49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_A2019StockOptionIncentivePlanMember_e274efba-9175-45a8-8f97-af0ef05850f8" xlink:href="acmr-20240331.xsd#acmr_A2019StockOptionIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_e0d81a31-a043-4821-9ff1-3668bae34f49" xlink:to="loc_acmr_A2019StockOptionIncentivePlanMember_e274efba-9175-45a8-8f97-af0ef05850f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_A2023StockOptionIncentivePlanMember_c6961905-c41b-442f-bcc3-4e382004a697" xlink:href="acmr-20240331.xsd#acmr_A2023StockOptionIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_e0d81a31-a043-4821-9ff1-3668bae34f49" xlink:to="loc_acmr_A2023StockOptionIncentivePlanMember_c6961905-c41b-442f-bcc3-4e382004a697" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_f73ad7d6-d157-43d0-af8a-d9313dcc3209" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_f73ad7d6-d157-43d0-af8a-d9313dcc3209" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_32f6713a-bbfc-419a-84a4-c7f9d4473534" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_f73ad7d6-d157-43d0-af8a-d9313dcc3209" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_32f6713a-bbfc-419a-84a4-c7f9d4473534" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_9bf2c948-73b7-46e1-a7ff-834578109ec3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_f73ad7d6-d157-43d0-af8a-d9313dcc3209" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_9bf2c948-73b7-46e1-a7ff-834578109ec3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_f2b0381f-9606-44e3-9c56-82cde59d339e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_f73ad7d6-d157-43d0-af8a-d9313dcc3209" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_f2b0381f-9606-44e3-9c56-82cde59d339e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_2f3ae10d-ff1b-4409-9d02-d94b2c3e0127" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_f73ad7d6-d157-43d0-af8a-d9313dcc3209" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_2f3ae10d-ff1b-4409-9d02-d94b2c3e0127" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_615f999c-2140-4d6c-8ab2-05e879a8f5db" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_d2e32e88-5c53-4f31-a90e-a68c90f57d3d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_f73ad7d6-d157-43d0-af8a-d9313dcc3209" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_d2e32e88-5c53-4f31-a90e-a68c90f57d3d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_464e5b91-1a6e-4beb-b3ed-ea4a524f0495" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_464e5b91-1a6e-4beb-b3ed-ea4a524f0495" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_f1465a87-da0f-4b9d-9edf-98ad09db3a2c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_464e5b91-1a6e-4beb-b3ed-ea4a524f0495" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_f1465a87-da0f-4b9d-9edf-98ad09db3a2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_19e02473-0ab2-4a1b-b59f-83d077a8dd3f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_464e5b91-1a6e-4beb-b3ed-ea4a524f0495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_19e02473-0ab2-4a1b-b59f-83d077a8dd3f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodWeightedAverageGrantDateFairValue_5239b19f-4d84-4c82-873c-4acd98340e17" xlink:href="acmr-20240331.xsd#acmr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_464e5b91-1a6e-4beb-b3ed-ea4a524f0495" xlink:to="loc_acmr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodWeightedAverageGrantDateFairValue_5239b19f-4d84-4c82-873c-4acd98340e17" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_6da9de47-990d-4a0c-b4ff-ededa9c0517e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_464e5b91-1a6e-4beb-b3ed-ea4a524f0495" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_6da9de47-990d-4a0c-b4ff-ededa9c0517e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_1a4dbd53-c089-4270-a3f0-42515f0543be" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_6c7b7957-f6a6-4d2a-a535-b74f19dd7cc1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_6c7b7957-f6a6-4d2a-a535-b74f19dd7cc1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_763e1b29-e1c4-45c9-a02c-9a1810a35103" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_6c7b7957-f6a6-4d2a-a535-b74f19dd7cc1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_763e1b29-e1c4-45c9-a02c-9a1810a35103" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_1c02aaba-c122-46bd-8289-7732f0bcaf02" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_6c7b7957-f6a6-4d2a-a535-b74f19dd7cc1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_1c02aaba-c122-46bd-8289-7732f0bcaf02" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_d661b1e9-3b65-436f-9af2-f7cb595f17f3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_6c7b7957-f6a6-4d2a-a535-b74f19dd7cc1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_d661b1e9-3b65-436f-9af2-f7cb595f17f3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_11b1f0c8-1c6c-47eb-a9c5-78312cc2c699" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_6c7b7957-f6a6-4d2a-a535-b74f19dd7cc1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_11b1f0c8-1c6c-47eb-a9c5-78312cc2c699" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_40036d98-cf55-4c72-9989-c831cee6d7f9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_b24b5290-da65-43f4-aba2-a9609fde5d21" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_b24b5290-da65-43f4-aba2-a9609fde5d21" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_20109ef4-5dc6-4351-ab37-06de3388c304" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_b24b5290-da65-43f4-aba2-a9609fde5d21" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_20109ef4-5dc6-4351-ab37-06de3388c304" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_865d64ec-0b61-4717-a62e-cdb0c7721b9a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_865d64ec-0b61-4717-a62e-cdb0c7721b9a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_de0486db-c5d8-48d8-aaeb-e1127ebb02e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_de0486db-c5d8-48d8-aaeb-e1127ebb02e0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_ccbebaf8-e4b2-4e71-904a-89b1f67b29ce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_ccbebaf8-e4b2-4e71-904a-89b1f67b29ce" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding_f2662d30-0659-47ca-8c5d-d01968206548" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding_f2662d30-0659-47ca-8c5d-d01968206548" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_5226869d-3724-4cef-8d52-e6d5facfc686" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_05cdceb6-1c86-4c2f-aefb-c1179d6f2a0f" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_5226869d-3724-4cef-8d52-e6d5facfc686" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/STOCKBASEDCOMPENSATIONAssumptionsUsedtoDetermineFairValueofShareOptionsGrantedDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#STOCKBASEDCOMPENSATIONAssumptionsUsedtoDetermineFairValueofShareOptionsGrantedDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/STOCKBASEDCOMPENSATIONAssumptionsUsedtoDetermineFairValueofShareOptionsGrantedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_62d09316-3a31-44f0-a1d8-a00aa8c29e83" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_aae1adb8-6351-4ad5-954a-951eee2508d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_62d09316-3a31-44f0-a1d8-a00aa8c29e83" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_aae1adb8-6351-4ad5-954a-951eee2508d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_d78b5c32-3054-4f90-8e97-a94ef91ec58b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_aae1adb8-6351-4ad5-954a-951eee2508d3" xlink:to="loc_us-gaap_AwardTypeAxis_d78b5c32-3054-4f90-8e97-a94ef91ec58b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d78b5c32-3054-4f90-8e97-a94ef91ec58b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_d78b5c32-3054-4f90-8e97-a94ef91ec58b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d78b5c32-3054-4f90-8e97-a94ef91ec58b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_948d6686-f586-47aa-aa19-06a659d299a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_d78b5c32-3054-4f90-8e97-a94ef91ec58b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_948d6686-f586-47aa-aa19-06a659d299a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_f2da5f23-10c9-458d-a838-0805f58a7eaa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_948d6686-f586-47aa-aa19-06a659d299a5" xlink:to="loc_us-gaap_EmployeeStockOptionMember_f2da5f23-10c9-458d-a838-0805f58a7eaa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_39927a89-56b3-440c-9c0a-5f5b9539209d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_aae1adb8-6351-4ad5-954a-951eee2508d3" xlink:to="loc_us-gaap_PlanNameAxis_39927a89-56b3-440c-9c0a-5f5b9539209d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_39927a89-56b3-440c-9c0a-5f5b9539209d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_39927a89-56b3-440c-9c0a-5f5b9539209d" xlink:to="loc_us-gaap_PlanNameDomain_39927a89-56b3-440c-9c0a-5f5b9539209d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_34431532-e648-423d-8805-5d68f92512c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_39927a89-56b3-440c-9c0a-5f5b9539209d" xlink:to="loc_us-gaap_PlanNameDomain_34431532-e648-423d-8805-5d68f92512c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ServicePeriodBasedApproachMember_c884716c-753a-48f8-ae81-6fc6b70cbcbe" xlink:href="acmr-20240331.xsd#acmr_ServicePeriodBasedApproachMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_34431532-e648-423d-8805-5d68f92512c2" xlink:to="loc_acmr_ServicePeriodBasedApproachMember_c884716c-753a-48f8-ae81-6fc6b70cbcbe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_A2023StockOptionIncentivePlanMember_3d62c0d8-87e9-4d04-b66c-590a00a9e985" xlink:href="acmr-20240331.xsd#acmr_A2023StockOptionIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_34431532-e648-423d-8805-5d68f92512c2" xlink:to="loc_acmr_A2023StockOptionIncentivePlanMember_3d62c0d8-87e9-4d04-b66c-590a00a9e985" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_8d4f8f4f-8586-4795-a03a-cb35880d74eb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_aae1adb8-6351-4ad5-954a-951eee2508d3" xlink:to="loc_srt_RangeAxis_8d4f8f4f-8586-4795-a03a-cb35880d74eb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_8d4f8f4f-8586-4795-a03a-cb35880d74eb_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_8d4f8f4f-8586-4795-a03a-cb35880d74eb" xlink:to="loc_srt_RangeMember_8d4f8f4f-8586-4795-a03a-cb35880d74eb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_8a32170c-92b2-4915-8e17-eaae902ab089" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_8d4f8f4f-8586-4795-a03a-cb35880d74eb" xlink:to="loc_srt_RangeMember_8a32170c-92b2-4915-8e17-eaae902ab089" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_722a9100-5ed6-4c11-b5bc-fdf8284e4a8b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_8a32170c-92b2-4915-8e17-eaae902ab089" xlink:to="loc_srt_MinimumMember_722a9100-5ed6-4c11-b5bc-fdf8284e4a8b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_75451bdd-213b-48c7-b738-7e5da7f2e05f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_8a32170c-92b2-4915-8e17-eaae902ab089" xlink:to="loc_srt_MaximumMember_75451bdd-213b-48c7-b738-7e5da7f2e05f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_91190e00-8b80-4b4f-a5a0-4fbee24badc4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_62d09316-3a31-44f0-a1d8-a00aa8c29e83" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_91190e00-8b80-4b4f-a5a0-4fbee24badc4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_98aecc4d-e758-4025-beb5-a16605ef4cab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_91190e00-8b80-4b4f-a5a0-4fbee24badc4" xlink:to="loc_us-gaap_SharePrice_98aecc4d-e758-4025-beb5-a16605ef4cab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_1be2e6f7-3d34-4c64-b79d-6113c3ddfe7c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_91190e00-8b80-4b4f-a5a0-4fbee24badc4" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_1be2e6f7-3d34-4c64-b79d-6113c3ddfe7c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_ea83c0d7-692e-4e85-9aca-86e631cffec6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_91190e00-8b80-4b4f-a5a0-4fbee24badc4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_ea83c0d7-692e-4e85-9aca-86e631cffec6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_2ab1312d-0e1a-48b3-b3da-d1782f4eef5b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_91190e00-8b80-4b4f-a5a0-4fbee24badc4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_2ab1312d-0e1a-48b3-b3da-d1782f4eef5b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_d35ea0e2-16d4-44fc-92d6-0fb185287cbf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_91190e00-8b80-4b4f-a5a0-4fbee24badc4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_d35ea0e2-16d4-44fc-92d6-0fb185287cbf" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/STOCKBASEDCOMPENSATIONStockbasedCompensationExpenseDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#STOCKBASEDCOMPENSATIONStockbasedCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/STOCKBASEDCOMPENSATIONStockbasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_ef1a7b79-473b-4e28-b003-866a34491a3c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_02c7fef6-9705-47e7-b91b-1dd120a2e280" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_ef1a7b79-473b-4e28-b003-866a34491a3c" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_02c7fef6-9705-47e7-b91b-1dd120a2e280" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_449f9ea0-a80c-4283-b026-649c22b8def5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_02c7fef6-9705-47e7-b91b-1dd120a2e280" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_449f9ea0-a80c-4283-b026-649c22b8def5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_449f9ea0-a80c-4283-b026-649c22b8def5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_449f9ea0-a80c-4283-b026-649c22b8def5" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_449f9ea0-a80c-4283-b026-649c22b8def5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_7323157f-554b-455d-8873-935433d9ebf0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_449f9ea0-a80c-4283-b026-649c22b8def5" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_7323157f-554b-455d-8873-935433d9ebf0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_6d9ae0af-611d-4628-a078-ccba05f4ade8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_7323157f-554b-455d-8873-935433d9ebf0" xlink:to="loc_us-gaap_CostOfSalesMember_6d9ae0af-611d-4628-a078-ccba05f4ade8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_038a3d23-9445-430a-9e29-5e4eb383c17a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SellingAndMarketingExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_7323157f-554b-455d-8873-935433d9ebf0" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_038a3d23-9445-430a-9e29-5e4eb383c17a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_3059e96e-5c43-4c74-b250-18e0d594f448" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_7323157f-554b-455d-8873-935433d9ebf0" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_3059e96e-5c43-4c74-b250-18e0d594f448" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_05d8803c-62c3-426b-bc61-ff7e3ffac268" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_7323157f-554b-455d-8873-935433d9ebf0" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_05d8803c-62c3-426b-bc61-ff7e3ffac268" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_e55d3f69-6b77-492f-b5ef-3a1efa1d9038" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_02c7fef6-9705-47e7-b91b-1dd120a2e280" xlink:to="loc_us-gaap_AwardTypeAxis_e55d3f69-6b77-492f-b5ef-3a1efa1d9038" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e55d3f69-6b77-492f-b5ef-3a1efa1d9038_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_e55d3f69-6b77-492f-b5ef-3a1efa1d9038" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e55d3f69-6b77-492f-b5ef-3a1efa1d9038_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_775e7c56-7dfd-439a-a652-1ed7c31daca5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_e55d3f69-6b77-492f-b5ef-3a1efa1d9038" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_775e7c56-7dfd-439a-a652-1ed7c31daca5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_75269463-7528-4704-8481-1e3921b9b5c0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_775e7c56-7dfd-439a-a652-1ed7c31daca5" xlink:to="loc_us-gaap_EmployeeStockOptionMember_75269463-7528-4704-8481-1e3921b9b5c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember_ec9264ca-baf2-4607-8f27-06d5b8ac33ba" xlink:href="acmr-20240331.xsd#acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_775e7c56-7dfd-439a-a652-1ed7c31daca5" xlink:to="loc_acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember_ec9264ca-baf2-4607-8f27-06d5b8ac33ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_27ff37ea-99df-4ea1-8ae6-af6bd9b97df1" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_02c7fef6-9705-47e7-b91b-1dd120a2e280" xlink:to="loc_srt_ConsolidatedEntitiesAxis_27ff37ea-99df-4ea1-8ae6-af6bd9b97df1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_27ff37ea-99df-4ea1-8ae6-af6bd9b97df1_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_27ff37ea-99df-4ea1-8ae6-af6bd9b97df1" xlink:to="loc_srt_ConsolidatedEntitiesDomain_27ff37ea-99df-4ea1-8ae6-af6bd9b97df1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_287a2f20-ce13-4d9d-bddb-310224c5b5bb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_27ff37ea-99df-4ea1-8ae6-af6bd9b97df1" xlink:to="loc_srt_ConsolidatedEntitiesDomain_287a2f20-ce13-4d9d-bddb-310224c5b5bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchShanghaiIncMember_fd8a445a-0be2-49e4-aad0-73975c7345bd" xlink:href="acmr-20240331.xsd#acmr_ACMResearchShanghaiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_287a2f20-ce13-4d9d-bddb-310224c5b5bb" xlink:to="loc_acmr_ACMResearchShanghaiIncMember_fd8a445a-0be2-49e4-aad0-73975c7345bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAbstract_83b16068-27c3-4345-8af3-04c2d80eb662" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_ef1a7b79-473b-4e28-b003-866a34491a3c" xlink:to="loc_us-gaap_ShareBasedCompensationAbstract_83b16068-27c3-4345-8af3-04c2d80eb662" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_728f85fd-39a1-4a7d-8ad9-384e5012a910" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationAbstract_83b16068-27c3-4345-8af3-04c2d80eb662" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_728f85fd-39a1-4a7d-8ad9-384e5012a910" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/INCOMETAXESNarrativeDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#INCOMETAXESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/INCOMETAXESNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_acmr_IncomeTaxesLineItems_bba20d57-c7f3-464b-9468-4bf276775d9e" xlink:href="acmr-20240331.xsd#acmr_IncomeTaxesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_IncomeTaxesTable_be28280d-dfc9-4549-976a-e20f481b6a88" xlink:href="acmr-20240331.xsd#acmr_IncomeTaxesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_acmr_IncomeTaxesLineItems_bba20d57-c7f3-464b-9468-4bf276775d9e" xlink:to="loc_acmr_IncomeTaxesTable_be28280d-dfc9-4549-976a-e20f481b6a88" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_f05c13f7-07ca-4d52-8d8c-1fd2874743bc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_IncomeTaxesTable_be28280d-dfc9-4549-976a-e20f481b6a88" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_f05c13f7-07ca-4d52-8d8c-1fd2874743bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_f05c13f7-07ca-4d52-8d8c-1fd2874743bc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_f05c13f7-07ca-4d52-8d8c-1fd2874743bc" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_f05c13f7-07ca-4d52-8d8c-1fd2874743bc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_b7c9212f-b788-454e-ae66-b451d40c4735" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_f05c13f7-07ca-4d52-8d8c-1fd2874743bc" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_b7c9212f-b788-454e-ae66-b451d40c4735" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_8bf5b382-fd52-4f17-adc0-24ff85c455fb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_b7c9212f-b788-454e-ae66-b451d40c4735" xlink:to="loc_us-gaap_ForeignCountryMember_8bf5b382-fd52-4f17-adc0-24ff85c455fb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_c61edc1b-ea40-4251-9d24-b96ca0bcda0b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_IncomeTaxesTable_be28280d-dfc9-4549-976a-e20f481b6a88" xlink:to="loc_srt_ConsolidatedEntitiesAxis_c61edc1b-ea40-4251-9d24-b96ca0bcda0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_c61edc1b-ea40-4251-9d24-b96ca0bcda0b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_c61edc1b-ea40-4251-9d24-b96ca0bcda0b" xlink:to="loc_srt_ConsolidatedEntitiesDomain_c61edc1b-ea40-4251-9d24-b96ca0bcda0b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_7d85dea3-9916-4b38-8c5d-587e5db657c1" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_c61edc1b-ea40-4251-9d24-b96ca0bcda0b" xlink:to="loc_srt_ConsolidatedEntitiesDomain_7d85dea3-9916-4b38-8c5d-587e5db657c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchShanghaiIncMember_bcffa95b-d727-4ab9-95d8-e9f369b1f5b7" xlink:href="acmr-20240331.xsd#acmr_ACMResearchShanghaiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7d85dea3-9916-4b38-8c5d-587e5db657c1" xlink:to="loc_acmr_ACMResearchShanghaiIncMember_bcffa95b-d727-4ab9-95d8-e9f369b1f5b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchWuxiIncMember_564fd7d8-b0ea-470b-9a30-bdcb623ed3f4" xlink:href="acmr-20240331.xsd#acmr_ACMResearchWuxiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7d85dea3-9916-4b38-8c5d-587e5db657c1" xlink:to="loc_acmr_ACMResearchWuxiIncMember_564fd7d8-b0ea-470b-9a30-bdcb623ed3f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchBeijingIncMember_644ed991-ee60-4c54-b400-6924172c157c" xlink:href="acmr-20240331.xsd#acmr_ACMResearchBeijingIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7d85dea3-9916-4b38-8c5d-587e5db657c1" xlink:to="loc_acmr_ACMResearchBeijingIncMember_644ed991-ee60-4c54-b400-6924172c157c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShengweiResearchShanghaiIncMember_68bdff69-3e90-4357-8954-1942db15bf79" xlink:href="acmr-20240331.xsd#acmr_ShengweiResearchShanghaiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7d85dea3-9916-4b38-8c5d-587e5db657c1" xlink:to="loc_acmr_ShengweiResearchShanghaiIncMember_68bdff69-3e90-4357-8954-1942db15bf79" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_0ebca478-9efc-43a3-9b5f-dc7ef5726a10" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acmr_IncomeTaxesTable_be28280d-dfc9-4549-976a-e20f481b6a88" xlink:to="loc_srt_RangeAxis_0ebca478-9efc-43a3-9b5f-dc7ef5726a10" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_0ebca478-9efc-43a3-9b5f-dc7ef5726a10_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_0ebca478-9efc-43a3-9b5f-dc7ef5726a10" xlink:to="loc_srt_RangeMember_0ebca478-9efc-43a3-9b5f-dc7ef5726a10_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b85217cc-46d0-4da0-a2d0-b45a700e57bf" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_0ebca478-9efc-43a3-9b5f-dc7ef5726a10" xlink:to="loc_srt_RangeMember_b85217cc-46d0-4da0-a2d0-b45a700e57bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_1b0bc961-a7fe-4559-aa5f-1cbbef480c82" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b85217cc-46d0-4da0-a2d0-b45a700e57bf" xlink:to="loc_srt_MinimumMember_1b0bc961-a7fe-4559-aa5f-1cbbef480c82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_cb4a05d9-78fd-4315-ab6a-3fc8f386721d" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b85217cc-46d0-4da0-a2d0-b45a700e57bf" xlink:to="loc_srt_MaximumMember_cb4a05d9-78fd-4315-ab6a-3fc8f386721d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acmr_IncomeTaxesLineItems_bba20d57-c7f3-464b-9468-4bf276775d9e" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ForeignCorporateTaxRate_159f8d4f-ef1d-456d-a4a0-c35bc63baafd" xlink:href="acmr-20240331.xsd#acmr_ForeignCorporateTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_acmr_ForeignCorporateTaxRate_159f8d4f-ef1d-456d-a4a0-c35bc63baafd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_d43574bb-0362-4767-b589-1236870e99eb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_d43574bb-0362-4767-b589-1236870e99eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAmortizationPeriod_a91dc64d-753e-441e-b105-b2095d1758c8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CapitalizedContractCostAmortizationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_us-gaap_CapitalizedContractCostAmortizationPeriod_a91dc64d-753e-441e-b105-b2095d1758c8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_4f15ed45-e595-4f29-b5b9-841da5118d34" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UnrecognizedTaxBenefits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_4f15ed45-e595-4f29-b5b9-841da5118d34" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_b71a4e4a-88d9-4a60-8931-e693326a61e8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_b71a4e4a-88d9-4a60-8931-e693326a61e8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_48f54f1b-f2e2-440b-9d00-efa1a1c88420" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_48f54f1b-f2e2-440b-9d00-efa1a1c88420" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_NumberOfSubsidiaries_d5142403-4384-4a2c-afb1-bb6e023fe45f" xlink:href="acmr-20240331.xsd#acmr_NumberOfSubsidiaries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_acmr_NumberOfSubsidiaries_d5142403-4384-4a2c-afb1-bb6e023fe45f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_00202b39-645e-4aae-b3c8-3a26342cc97f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_00202b39-645e-4aae-b3c8-3a26342cc97f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_EffectivePeriodOfPreferentialIncomeTaxRate_fcece114-1a22-49bc-93d1-46c04349d05f" xlink:href="acmr-20240331.xsd#acmr_EffectivePeriodOfPreferentialIncomeTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_ee4f5cf1-76c8-497a-a74b-efc5db24d3d0" xlink:to="loc_acmr_EffectivePeriodOfPreferentialIncomeTaxRate_fcece114-1a22-49bc-93d1-46c04349d05f" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/SEGMENTINFORMATIONDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#SEGMENTINFORMATIONDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/SEGMENTINFORMATIONDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_1757eb56-1ae8-409a-99dc-307d55d4ea6f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_c13de5cc-f51c-4559-8adf-615762af7767" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1757eb56-1ae8-409a-99dc-307d55d4ea6f" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_c13de5cc-f51c-4559-8adf-615762af7767" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_b11c15e2-6f8c-4814-a768-c4228978b44b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_c13de5cc-f51c-4559-8adf-615762af7767" xlink:to="loc_srt_StatementGeographicalAxis_b11c15e2-6f8c-4814-a768-c4228978b44b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_b11c15e2-6f8c-4814-a768-c4228978b44b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_b11c15e2-6f8c-4814-a768-c4228978b44b" xlink:to="loc_srt_SegmentGeographicalDomain_b11c15e2-6f8c-4814-a768-c4228978b44b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_17306209-c7ba-4d57-b73d-305da4964cd3" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_b11c15e2-6f8c-4814-a768-c4228978b44b" xlink:to="loc_srt_SegmentGeographicalDomain_17306209-c7ba-4d57-b73d-305da4964cd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_8a07b47c-96a2-44d6-b005-17be2841b976" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_17306209-c7ba-4d57-b73d-305da4964cd3" xlink:to="loc_country_CN_8a07b47c-96a2-44d6-b005-17be2841b976" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_KR_cf5926d7-581c-459d-9c6d-eba51f88d512" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_KR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_17306209-c7ba-4d57-b73d-305da4964cd3" xlink:to="loc_country_KR_cf5926d7-581c-459d-9c6d-eba51f88d512" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_c8c7a2b1-104b-4c72-81e8-052194779694" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_17306209-c7ba-4d57-b73d-305da4964cd3" xlink:to="loc_country_US_c8c7a2b1-104b-4c72-81e8-052194779694" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicAreasLongLivedAssetsAbstract_6ef33461-16d6-4464-9fc6-3e60d7960ad9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GeographicAreasLongLivedAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1757eb56-1ae8-409a-99dc-307d55d4ea6f" xlink:to="loc_us-gaap_GeographicAreasLongLivedAssetsAbstract_6ef33461-16d6-4464-9fc6-3e60d7960ad9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncurrentAssets_5e7f2e80-86e2-4363-b081-e34146b44266" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GeographicAreasLongLivedAssetsAbstract_6ef33461-16d6-4464-9fc6-3e60d7960ad9" xlink:to="loc_us-gaap_NoncurrentAssets_5e7f2e80-86e2-4363-b081-e34146b44266" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_3a6e0938-db6c-4b01-a52d-e8edaf471512" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1757eb56-1ae8-409a-99dc-307d55d4ea6f" xlink:to="loc_us-gaap_NumberOfOperatingSegments_3a6e0938-db6c-4b01-a52d-e8edaf471512" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://acmrcsh.com/role/STATUTORYSURPLUSRESERVEDetails" xlink:type="simple" xlink:href="acmr-20240331.xsd#STATUTORYSURPLUSRESERVEDetails"/>
  <link:definitionLink xlink:role="http://acmrcsh.com/role/STATUTORYSURPLUSRESERVEDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatutoryAccountingPracticesLineItems_4eb9031e-5908-4f7e-988c-9762db4fedd3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatutoryAccountingPracticesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatutoryAccountingPracticesTable_b8fad658-26e4-4cac-bfec-3e84254102bc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatutoryAccountingPracticesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatutoryAccountingPracticesLineItems_4eb9031e-5908-4f7e-988c-9762db4fedd3" xlink:to="loc_us-gaap_StatutoryAccountingPracticesTable_b8fad658-26e4-4cac-bfec-3e84254102bc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_f78413bd-246d-4572-9193-37b3ee077b66" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatutoryAccountingPracticesTable_b8fad658-26e4-4cac-bfec-3e84254102bc" xlink:to="loc_srt_ConsolidatedEntitiesAxis_f78413bd-246d-4572-9193-37b3ee077b66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_f78413bd-246d-4572-9193-37b3ee077b66_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_f78413bd-246d-4572-9193-37b3ee077b66" xlink:to="loc_srt_ConsolidatedEntitiesDomain_f78413bd-246d-4572-9193-37b3ee077b66_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_6b8ddcfe-5e54-4b8a-bba3-87592dfde24a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_f78413bd-246d-4572-9193-37b3ee077b66" xlink:to="loc_srt_ConsolidatedEntitiesDomain_6b8ddcfe-5e54-4b8a-bba3-87592dfde24a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ACMResearchShanghaiIncMember_434fb715-7253-4620-9388-f6ec6cba9094" xlink:href="acmr-20240331.xsd#acmr_ACMResearchShanghaiIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_6b8ddcfe-5e54-4b8a-bba3-87592dfde24a" xlink:to="loc_acmr_ACMResearchShanghaiIncMember_434fb715-7253-4620-9388-f6ec6cba9094" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficitAbstract_821d6bce-ede9-485e-a88d-4c6e8efa355e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficitAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatutoryAccountingPracticesLineItems_4eb9031e-5908-4f7e-988c-9762db4fedd3" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficitAbstract_821d6bce-ede9-485e-a88d-4c6e8efa355e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance_f06ca7d7-9308-4845-a99c-d70192428655" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetainedEarningsAccumulatedDeficitAbstract_821d6bce-ede9-485e-a88d-4c6e8efa355e" xlink:to="loc_us-gaap_StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance_f06ca7d7-9308-4845-a99c-d70192428655" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd#AwardTypeOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember_abf00f38-a0eb-426f-9bed-df385f33df73" xlink:href="acmr-20240331.xsd#acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_acmr_ShareBasedPaymentArrangementNonEmployeeStockOptionMember_abf00f38-a0eb-426f-9bed-df385f33df73" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_JianWangMember_8f26d71a-5516-47af-974c-5f11a4239830" xlink:href="acmr-20240331.xsd#acmr_JianWangMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_acmr_JianWangMember_8f26d71a-5516-47af-974c-5f11a4239830" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_MarkMcKechnieMember_877f8f9e-42d1-4fc6-bedd-b7efbe739764" xlink:href="acmr-20240331.xsd#acmr_MarkMcKechnieMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_acmr_MarkMcKechnieMember_877f8f9e-42d1-4fc6-bedd-b7efbe739764" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acmr_LisaFengMember_6955771c-3255-4ad2-acdc-1f1d19153c42" xlink:href="acmr-20240331.xsd#acmr_LisaFengMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_acmr_LisaFengMember_6955771c-3255-4ad2-acdc-1f1d19153c42" xlink:type="arc" order="4"/>
  </link:definitionLink>
</link:linkbase>
