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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,
 IXDXOezJH8A8rUIITXsuANDzFeZGiB2HR4iI6fx6QBakEsdV4cUWVM9+FnQ1RaJ5
 6ILEGl2DxOXmitEXMYrZkg==

<SEC-DOCUMENT>0001127602-11-002670.txt : 20110128
<SEC-HEADER>0001127602-11-002670.hdr.sgml : 20110128
<ACCEPTANCE-DATETIME>20110128155012
ACCESSION NUMBER:		0001127602-11-002670
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101231
FILED AS OF DATE:		20110128
DATE AS OF CHANGE:		20110128

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SMITH MARSCHALL
		CENTRAL INDEX KEY:			0001220974

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-03285
		FILM NUMBER:		11555786

	MAIL ADDRESS:	
		STREET 1:		3M COMPANY
		STREET 2:		3M CENTER, BLDG. 0220-11-W-02
		CITY:			ST PAUL
		STATE:			MN
		ZIP:			551441000

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			3M CO
		CENTRAL INDEX KEY:			0000066740
		STANDARD INDUSTRIAL CLASSIFICATION:	SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
		IRS NUMBER:				410417775
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3M CENTER
		STREET 2:		BLDG. 220-11W-02
		CITY:			ST PAUL
		STATE:			MN
		ZIP:			55144-1000
		BUSINESS PHONE:		6517332204

	MAIL ADDRESS:	
		STREET 1:		3M CENTER
		STREET 2:		BLDG. 220-11W-02
		CITY:			ST. PAUL
		STATE:			MN
		ZIP:			55144-1000

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MINNESOTA MINING & MANUFACTURING CO
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>form5.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2010-12-31</periodOfReport>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000066740</issuerCik>
        <issuerName>3M CO</issuerName>
        <issuerTradingSymbol>MMM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220974</rptOwnerCik>
            <rptOwnerName>SMITH MARSCHALL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3M CENTER</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ST. PAUL</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55144-1000</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>VICE PRESIDENT LEGAL</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>359</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401k/Paesop Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Includes shares acquired during the fiscal year pursuant to the 3M Voluntary Investment Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>George Ann Biros, attorney-in-fact for Marschall Smith</signatureName>
        <signatureDate>2011-01-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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