-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 AfMNhxTXbPpLnI0H9Y7QMSeDWVseOLwfJM+gzZKQ0Z2UdyeHf3GK5kYfTn48o17V
 FCsAQfegRN8Ot1SEsBjX+Q==

<SEC-DOCUMENT>0001140361-10-020634.txt : 20100512
<SEC-HEADER>0001140361-10-020634.hdr.sgml : 20100512
<ACCEPTANCE-DATETIME>20100512140007
ACCESSION NUMBER:		0001140361-10-020634
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100510
FILED AS OF DATE:		20100512
DATE AS OF CHANGE:		20100512

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MEMSIC Inc
		CENTRAL INDEX KEY:			0001386198
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				000000000
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		800 Turnpike Street
		CITY:			North Andover
		STATE:			MA
		ZIP:			01845
		BUSINESS PHONE:		9787380900

	MAIL ADDRESS:	
		STREET 1:		800 Turnpike Street
		CITY:			North Andover
		STATE:			MA
		ZIP:			01845

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			AMERIPRISE FINANCIAL INC
		CENTRAL INDEX KEY:			0000820027
		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33813
		FILM NUMBER:		10823774

	BUSINESS ADDRESS:	
		STREET 1:		1099 AMERIPRISE FINANCIAL CENTER
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55474
		BUSINESS PHONE:		612-671-2018

	MAIL ADDRESS:	
		STREET 1:		1099 AMERIPRISE FINANCIAL CENTER
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55474

	FORMER NAME:	
		FORMER CONFORMED NAME:	AMERICAN EXPRESS FINANCIAL CORP
		DATE OF NAME CHANGE:	20030513

	FORMER NAME:	
		FORMER CONFORMED NAME:	AMERICAN EXPRESS FINANCIAL ADVISORS
		DATE OF NAME CHANGE:	19950711

	FORMER NAME:	
		FORMER CONFORMED NAME:	IDS FINANCIAL CORP/MN/
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RIVERSOURCE INVESTMENTS LLC
		CENTRAL INDEX KEY:			0001233991
		STATE OF INCORPORATION:			MN

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33813
		FILM NUMBER:		10823775

	BUSINESS ADDRESS:	
		STREET 1:		50606 AMERIPRISE FINANCIAL CENTER
		STREET 2:		(H27/5228)
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55474
		BUSINESS PHONE:		612-671-4321

	MAIL ADDRESS:	
		STREET 1:		50606 AMERIPRISE FINANCIAL CENTER
		STREET 2:		(H27/5228)
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55474

	FORMER NAME:	
		FORMER CONFORMED NAME:	AMERICAN EXPRESS ASSET MANAGEMENT GROUP INC
		DATE OF NAME CHANGE:	20030519
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-05-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001386198</issuerCik>
        <issuerName>MEMSIC Inc</issuerName>
        <issuerTradingSymbol>MEMS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001233991</rptOwnerCik>
            <rptOwnerName>RIVERSOURCE INVESTMENTS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 AMERIPRISE FINANCIAL CENTER</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MINNEAPOLIS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55474</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000820027</rptOwnerCik>
            <rptOwnerName>AMERIPRISE FINANCIAL INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 AMERIPRISE FINANCIAL CENTER</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MINNEAPOLIS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55474</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-10</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.3100</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3014729</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Investment Adviser on behalf of clients</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-10</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>41500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.3279</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3056229</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Investment Adviser on behalf of clients</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-10</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6200</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.3100</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3062429</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Investment Adviser on behalf of clients</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-11</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>22700</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.2492</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3085129</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Investment Adviser on behalf of clients</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <remarks>This statement is filed pursuant to Section 16 of the Act and shall not be deemed an admission that the reporting person are, for purposes of Section 16 of the Act or otherwise, the beneficial owners of these securities.</remarks>

    <ownerSignature>
        <signatureName>/s/ David H. Weiser, SVP and Assistant General Counsel, Ameriprise Financial, Inc.</signatureName>
        <signatureDate>2010-05-12</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Paul B. Goucher, Assistant Secretary of Investment Adviser</signatureName>
        <signatureDate>2010-05-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----