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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,
 NzlX++y3vcMQMFfxkUL35rmBoO8z+6RyDQsYN9o2PncOsB0ZqsHq7U6fvMmUs3e5
 SZXxvNhEc2xkJE4scqsQDA==

<SEC-DOCUMENT>0000916076-06-000095.txt : 20060404
<SEC-HEADER>0000916076-06-000095.hdr.sgml : 20060404
<ACCEPTANCE-DATETIME>20060404152554
ACCESSION NUMBER:		0000916076-06-000095
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060331
FILED AS OF DATE:		20060404
DATE AS OF CHANGE:		20060404

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARTIN MARIETTA MATERIALS INC
		CENTRAL INDEX KEY:			0000916076
		STANDARD INDUSTRIAL CLASSIFICATION:	MINING, QUARRYING OF NONMETALLIC MINERALS (NO FUELS) [1400]
		IRS NUMBER:				561848578
		STATE OF INCORPORATION:			NC
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2710 WYCLIFF RD
		CITY:			RALEIGH
		STATE:			NC
		ZIP:			27607
		BUSINESS PHONE:		9197814550

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BENNETT MARCUS C
		CENTRAL INDEX KEY:			0001084479
		STANDARD INDUSTRIAL CLASSIFICATION:	MINING, QUARRYING OF NONMETALLIC MINERALS (NO FUELS) [1400]
		STATE OF INCORPORATION:			NC
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12744
		FILM NUMBER:		06737729

	BUSINESS ADDRESS:	
		STREET 1:		C/O CARPENTER TECHNOLOGY CORP
		STREET 2:		1047 NORTH PARK ROAD
		CITY:			WYOMISSING
		STATE:			PA
		ZIP:			19610
		BUSINESS PHONE:		6102082673

	MAIL ADDRESS:	
		STREET 2:		1047 NORTH PARK ROAD
		CITY:			WYOMISSING
		STATE:			PA
		ZIP:			19610
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-03-31</periodOfReport>

    <issuer>
        <issuerCik>0000916076</issuerCik>
        <issuerName>MARTIN MARIETTA MATERIALS INC</issuerName>
        <issuerTradingSymbol>MLM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001084479</rptOwnerCik>
            <rptOwnerName>BENNETT MARCUS C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2710 WYCLIFF ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RALEIGH</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>27607</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2006-03-31</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>88</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>85.62</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5273</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F2">balance transfer from previous software -- includes 4,000 shares previously directly held (not from Directors Plan)</footnote>
        <footnote id="F1">Common stock units were accrued under the Martin Marietta Materials, Inc. Common Stock Purchase Plan for Directors (the &quot;Plan&quot;) and are to be settled in stock in a lump sum or in installments not to exceed 10 years commencing on (i) the date the reporting person ceases to be a Non-Employee Director or (ii) the date that is one month and one year following the date the reporting person ceases to be a Non-Employee Director, in accordance with the reporting person's election under the Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Roselyn R. Bar, attorney-in-fact</signatureName>
        <signatureDate>2006-04-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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