content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
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  <submissionType>144</submissionType>
  <filerInfo>
  <filer>
  <filerCredentials>
  <cik>0001960524</cik>
  <ccc>XXXXXXXX</ccc>
  </filerCredentials>
  </filer>
  <liveTestFlag>LIVE</liveTestFlag>
  
  
  
  </filerInfo>
  </headerData>
  <formData>
  <issuerInfo>
  <issuerCik>0001990550</issuerCik>
  <issuerName>Ambrx Biopharma, Inc.</issuerName>
  <secFileNumber>000-56600</secFileNumber>
  <issuerAddress>
  <com:street1>10975 North Torrey Pines Road</com:street1>
  <com:city>La Jolla</com:city>
  <com:stateOrCountry>CA</com:stateOrCountry>
  <com:zipCode>92037</com:zipCode>
  </issuerAddress>
  <issuerContactPhone>(858) 875-2400</issuerContactPhone>
  <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>HOPU Reunion Co Ltd</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
  <relationshipsToIssuer>
  <relationshipToIssuer>Affiliated with former director</relationshipToIssuer>
  </relationshipsToIssuer>
  </issuerInfo>
  <securitiesInformation>
  <securitiesClassTitle>Common Stock</securitiesClassTitle>
  <brokerOrMarketmakerDetails>
  <name>Citigroup Global Markets Inc.</name>
  <address>
  <com:street1>388 Greenwich Street</com:street1>
  <com:street2>Trading Building - 4th Floor</com:street2>
  <com:city>New York</com:city>
  <com:stateOrCountry>NY</com:stateOrCountry>
  <com:zipCode>10013</com:zipCode>
  </address>
  </brokerOrMarketmakerDetails>
  <noOfUnitsSold>600000</noOfUnitsSold>
  <aggregateMarketValue>7032000</aggregateMarketValue>
  <noOfUnitsOutstanding>63150244</noOfUnitsOutstanding>
  <approxSaleDate>12/01/2023</approxSaleDate>
  <securitiesExchangeName>NASDAQ</securitiesExchangeName>
  </securitiesInformation>
  <securitiesToBeSold>
  <securitiesClassTitle>Common Stock</securitiesClassTitle>
  <acquiredDate>04/04/2018</acquiredDate>
  <natureOfAcquisitionTransaction>Private purchase agreement</natureOfAcquisitionTransaction>
  <nameOfPersonfromWhomAcquired>Another shareholder</nameOfPersonfromWhomAcquired>
  <isGiftTransaction>N</isGiftTransaction>
  <amountOfSecuritiesAcquired>5692857</amountOfSecuritiesAcquired>
  <paymentDate>04/04/2018</paymentDate>
  <natureOfPayment>Cash</natureOfPayment>
  </securitiesToBeSold>
  <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
  <noticeSignature>
  <noticeDate>12/01/2023</noticeDate>
  <signature>/s/ Xiaowei Chang, Director of HOPU Reunion Company Limited</signature>
  </noticeSignature>
  </formData>
  </edgarSubmission>
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text: 144
  0001960524
  XXXXXXXX
  LIVE
  0001990550
  Ambrx Biopharma, Inc.
  000-56600
  10975 North Torrey Pines Road
  La Jolla
  CA
  92037
  (858) 875-2400
  HOPU Reunion Co Ltd
  Affiliated with former director
  Common Stock
  Citigroup Global Markets Inc.
  388 Greenwich Street
  Trading Building - 4th Floor
  New York
  NY
  10013
  600000
  7032000
  63150244
  12/01/2023
  NASDAQ
  Common Stock
  04/04/2018
  Private purchase agreement
  Another shareholder
  N
  5692857
  04/04/2018
  Cash
  Y
  12/01/2023
  /s/ Xiaowei Chang, Director of HOPU Reunion Company Limited