<SUBMISSION>
<ACCESSION-NUMBER>0001476753-09-000001
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20091105
<FILING-DATE>20091116
<DATE-OF-FILING-DATE-CHANGE>20091116
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Marks Jeffrey
<CIK>0001476753
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>000-12933
<FILM-NUMBER>091185875
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>4650 CUSHING PARKWAY
<CITY>FREMONT
<STATE>CA
<ZIP>94538
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>LAM RESEARCH CORP
<CIK>0000707549
<ASSIGNED-SIC>3559
<IRS-NUMBER>942634797
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>0629
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>4650 CUSHING BLVD
<CITY>FREMONT
<STATE>CA
<ZIP>94538
<PHONE>5106590200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>4650 CUSHING PARKWAY
<CITY>FREMONT
<STATE>CA
<ZIP>94538
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2009-11-05</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000707549</issuerCik>
        <issuerName>LAM RESEARCH CORP</issuerName>
        <issuerTradingSymbol>LRCX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001476753</rptOwnerCik>
            <rptOwnerName>Marks Jeffrey</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4650 CUSHING PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FREMONT</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP &amp; GM, Clean Business</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>46747</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>20.21</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-02-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>28760</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Stock option will vest 100% on 02/26/11</footnote>
        <footnote id="F2">Includes 33,504 Restricted Stock Units</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Kym Hall by Power of Attorney</signatureName>
        <signatureDate>2009-11-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
