-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 GHesF9CB5bMIrvpdteCum0zcP6sBGyPNSkSBfcSnfjVjE40EBaTrM+/LbpJVyLJA
 hUiL+LPb2sw/WyO3xOAIww==

<SEC-DOCUMENT>0001179110-10-017820.txt : 20101217
<SEC-HEADER>0001179110-10-017820.hdr.sgml : 20101217
<ACCEPTANCE-DATETIME>20101217174401
ACCESSION NUMBER:		0001179110-10-017820
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101215
FILED AS OF DATE:		20101217
DATE AS OF CHANGE:		20101217

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MALONE JOHN C
		CENTRAL INDEX KEY:			0000937797
		STATE OF INCORPORATION:			CO
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33982
		FILM NUMBER:		101260925

	MAIL ADDRESS:	
		STREET 1:		12300 LIBERTY BLVD
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LIBERTY MEDIA CORP
		CENTRAL INDEX KEY:			0001355096
		STANDARD INDUSTRIAL CLASSIFICATION:	CABLE & OTHER PAY TELEVISION SERVICES [4841]
		IRS NUMBER:				841288730
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		12300 LIBERTY BOULEVARD
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112
		BUSINESS PHONE:		7208755400

	MAIL ADDRESS:	
		STREET 1:		12300 LIBERTY BOULEVARD
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Liberty Media Holding CORP
		DATE OF NAME CHANGE:	20060303
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-12-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001355096</issuerCik>
        <issuerName>LIBERTY MEDIA CORP</issuerName>
        <issuerTradingSymbol>LSTZA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000937797</rptOwnerCik>
            <rptOwnerName>MALONE JOHN C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12300 LIBERTY BLVD.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ENGLEWOOD</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80112</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman of the Board</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series A Liberty Starz Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>782</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>68.16</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17457</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Series A Liberty Starz Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30100</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Series A Liberty Starz Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>66</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Series A Liberty Starz Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>513</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) Savings Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The shares disposed of in the transaction were withheld by the Issuer in connection with the payment of withholding taxes on restricted shares that vested as of December 15, 2010. The price is based on an average of the high and low trading prices on December 15, 2010.</footnote>
        <footnote id="F2">The Reporting Person disclaims beneficial ownership of these shares owned by his spouse.</footnote>
        <footnote id="F3">The Reporting Person is the sole trustee of, and with his spouse retains a unitrust interest in, the trust.</footnote>
        <footnote id="F4">The number of shares reported as held in the reporting person's 401(k) is based on a plan statement from the Plan Administrator for the Issuer's 401(k) Savings Plan dated as of November 30, 2010.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ John C. Malone</signatureName>
        <signatureDate>2010-12-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----