-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 RITnBxZ5IfbjLV7VSxvfBnBty6EBYbRNRFjKKfqruRJ/2eUdJDxC6yZA2+kPZQlu
 umPFjbJFXhSrwtOSoJYkDA==

<SEC-DOCUMENT>0000754673-10-000104.txt : 20100928
<SEC-HEADER>0000754673-10-000104.hdr.sgml : 20100928
<ACCEPTANCE-DATETIME>20100928141532
ACCESSION NUMBER:		0000754673-10-000104
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100927
FILED AS OF DATE:		20100928
DATE AS OF CHANGE:		20100928

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Stark John D JR
		CENTRAL INDEX KEY:			0001403610

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-13580
		FILM NUMBER:		101093241

	MAIL ADDRESS:	
		STREET 1:		700 MIDDLE ROAD
		CITY:			RIVERHEAD
		STATE:			NY
		ZIP:			11901

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SUFFOLK BANCORP
		CENTRAL INDEX KEY:			0000754673
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				112708279
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6 W SECOND ST
		CITY:			RIVERHEAD
		STATE:			NY
		ZIP:			11901
		BUSINESS PHONE:		5167275667

	MAIL ADDRESS:	
		STREET 1:		6 WEST SECOND STREET
		CITY:			RIVERHEAD
		STATE:			NY
		ZIP:			11901
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-09-27</periodOfReport>

    <issuer>
        <issuerCik>0000754673</issuerCik>
        <issuerName>SUFFOLK BANCORP</issuerName>
        <issuerTradingSymbol>SUBK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001403610</rptOwnerCik>
            <rptOwnerName>Stark John D JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SUFFOLK BANCORP</rptOwnerStreet1>
            <rptOwnerStreet2>4 WEST SECOND STREET, P.O. BOX 9000</rptOwnerStreet2>
            <rptOwnerCity>RIVERHEAD</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11901</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Suffolk Bancorp Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-09-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>103.77</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.1721</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29502.677</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Douglas Ian Shaw Power of Attorney for John D. Stark JR</signatureName>
        <signatureDate>2010-09-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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