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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 POz+OG54s4/mGCGUk5ZydbPd3pLLltvO2gCLg5wIjsSyb51FFdHhBqHvpL5MW9jV
 KsuUUUpZ9Z+lbHeSWg6++w==

<SEC-DOCUMENT>0001329049-06-000001.txt : 20060202
<SEC-HEADER>0001329049-06-000001.hdr.sgml : 20060202
<ACCEPTANCE-DATETIME>20060202200258
ACCESSION NUMBER:		0001329049-06-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060131
FILED AS OF DATE:		20060202
DATE AS OF CHANGE:		20060202

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CHIRON CORP
		CENTRAL INDEX KEY:			0000706539
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				942754624
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4560 HORTON ST
		CITY:			EMERYVILLE
		STATE:			CA
		ZIP:			94608
		BUSINESS PHONE:		5106558730

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			White David
		CENTRAL INDEX KEY:			0001329049

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-12798
		FILM NUMBER:		06575290

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		510-923-3969

	MAIL ADDRESS:	
		STREET 1:		4560 HORTON STREET
		CITY:			EMERYVILLE
		STATE:			CA
		ZIP:			94608
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-01-31</periodOfReport>

    <issuer>
        <issuerCik>0000706539</issuerCik>
        <issuerName>CHIRON CORP</issuerName>
        <issuerTradingSymbol>CHIR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001329049</rptOwnerCik>
            <rptOwnerName>White David</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4560 HORTON STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>EMERYVILLE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94608</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP, Controller</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-01-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-01-31</value>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2008-01-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each unit pertains to one share of the Issuer's common stock  and may be settled either in cash or in stock based on date on which settlement occurs.  Settlement will occur as the units vest, and to the extent such settlement occurs prior to the closing of the acquisition of the Issuer by Novartis AG, the payment will be made in shares of the Issuer's common stock; otherwise, the units will be assumed by Novartis and payment will be made in cash based on the consideration paid per share of the Issuer's common stock in the Novartis acquisition.</footnote>
        <footnote id="F2">One-for-One</footnote>
        <footnote id="F3">Shares of the Issuer's common stock which become issuable upon the vesting of the units may, at the Reporting Person's election, be withheld by the Issuer in satisfaction  of the applicable withholding taxes.</footnote>
        <footnote id="F4">40% of the units will vest upon the Reporting Person's completion of one year of employment with the Issuer measured from the award date, and the remaining 60% will vest upon his completion of two years of such employment.  However, the units will vest in full on an accelerated basis upon an acquisition of the Issuer by a merger or asset sale  in which the units are not assumed or upon the  termination of the Reporting Person's employment with the Issuer under certain prescribed circumstances following certain changes in control or ownership of the Issuer (including the Novartis acquisition) in which the units are assumed.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>David A. White by Naima Robinson as Atty-in-Fact</signatureName>
        <signatureDate>2006-02-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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