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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 A2JB9zUs8a5kLU2l7+kKPmc+I6aipWpxzYlkP3gXXoKgmokpkQTjZn1FM83Z0XCL
 q0MIt2aF+ymWKS3GaufysA==

<SEC-DOCUMENT>0001181431-04-059106.txt : 20041215
<SEC-HEADER>0001181431-04-059106.hdr.sgml : 20041215
<ACCEPTANCE-DATETIME>20041215214745
ACCESSION NUMBER:		0001181431-04-059106
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041213
FILED AS OF DATE:		20041215
DATE AS OF CHANGE:		20041215

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHEN DAVID
		CENTRAL INDEX KEY:			0001189015

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-33407
		FILM NUMBER:		041206283

	BUSINESS ADDRESS:	
		STREET 1:		11777 SAN VICENTE BLVD
		STREET 2:		STE 550
		CITY:			WEST LOS ANGELES
		STATE:			CA
		ZIP:			90024
		BUSINESS PHONE:		3104704222

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMERICAN PHARMACEUTICAL PARTNERS INC /DE/
		CENTRAL INDEX KEY:			0001141399
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				680389419
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1501 EAST WOODFIELD ROAD
		STREET 2:		SUITE 300 EAST
		CITY:			SCHAUMBURG
		STATE:			IL
		ZIP:			60173-5837
		BUSINESS PHONE:		847-969-2700

	MAIL ADDRESS:	
		STREET 1:		1501 EAST WOODFIELD ROAD
		STREET 2:		SUITE 300 EAST
		CITY:			SCHAUMBURG
		STATE:			IL
		ZIP:			60173-5837

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AMERICAN PHARMACEUTICAL PARTNERS INC /CA/
		DATE OF NAME CHANGE:	20010525
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd61583.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-12-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001141399</issuerCik>
        <issuerName>AMERICAN PHARMACEUTICAL PARTNERS INC /DE/</issuerName>
        <issuerTradingSymbol>APPX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001189015</rptOwnerCik>
            <rptOwnerName>CHEN DAVID</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1501 EAST WOODFIELD ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 300 EAST</rptOwnerStreet2>
            <rptOwnerCity>SCHAUMBURG</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60173-5837</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Nonqualified Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>35.19</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-12-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2005-12-13</value>
            </exerciseDate>
            <expirationDate>
                <value>2014-12-13</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>/s/ Jack C. Silhavy by power of attorney for David Chen</signatureName>
        <signatureDate>2004-12-15</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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