-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 VMZtHSai5ty3T+1EZL910joG+GVkDIcE2VoihgPjxeblca9rGK0Yv6Y7CP9VWZDO
 fWY9MZDV/lOeZCtJ9u4ZoQ==

<SEC-DOCUMENT>0001179110-04-005450.txt : 20040305
<SEC-HEADER>0001179110-04-005450.hdr.sgml : 20040305
<ACCEPTANCE-DATETIME>20040305144257
ACCESSION NUMBER:		0001179110-04-005450
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031210
FILED AS OF DATE:		20040305

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SIMON PROPERTY GROUP INC /DE/
		CENTRAL INDEX KEY:			0001063761
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				046268599
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		115 WEST WASHINGTON STREET
		CITY:			INDIANAPOLIS
		STATE:			IN
		ZIP:			46204
		BUSINESS PHONE:		3176361600

	MAIL ADDRESS:	
		STREET 1:		115 WEST WASHINGTON STREET
		STREET 2:		-
		CITY:			INDIANAPOLIS
		STATE:			IN
		ZIP:			46204

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CORPORATE PROPERTY INVESTORS INC
		DATE OF NAME CHANGE:	19980610

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MAUTNER HANS C
		CENTRAL INDEX KEY:			0001070947

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14469
		FILM NUMBER:		04651627

	BUSINESS ADDRESS:	
		STREET 1:		C/O DREYFUS CORP
		STREET 2:		200 PARK AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10166
		BUSINESS PHONE:		2129226000

	MAIL ADDRESS:	
		STREET 1:		PGGM KROOSTWEG NOORD 149
		STREET 2:		POSTBUS 117
		CITY:			3700 AC ZEIST NETHER
		STATE:			P7
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-12-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001063761</issuerCik>
        <issuerName>SIMON PROPERTY GROUP INC /DE/</issuerName>
        <issuerTradingSymbol>SPG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001070947</rptOwnerCik>
            <rptOwnerName>MAUTNER HANS C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>33 ST. JAMES SQUARE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LONDON</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode>SW1Y 4JS</rptOwnerZipCode>
            <rptOwnerStateDescription>NETHERLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President- International Div.</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-12-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>26432</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-12-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>68354</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>354074</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person converted each share of Series B Preferred Stock into 2.58605 shares of Common Stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Hans C. Mautner, and his attorney-in-fact, Shelly Doran</signatureName>
        <signatureDate>2004-03-05</signatureDate>
    </ownerSignature>
</ownershipDocument>

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