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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

(Mark one)

For the fiscal year ended: December 31, 2009

OR

Commission file number: 001-33813

MEMSIC, INC.

(Exact name of registrant as specified in its charter)

One Tech Drive, Suite 325,

Andover, MA 01810

Telephone: (978)738-0900

(Address, including zip code, and telephone number, including

area code, of registrant’s principal executive offices)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(b) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨    No  x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act.    Yes  ¨    No    x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  ¨    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

As of June 30, 2009 (the last business day of the registrant’s most recently completed second fiscal quarter), the aggregate market value of voting stock held by non-affiliates of the registrant was approximately $67,500,058.

On April 28, 2010, 23,804,863 shares of our common stock were outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

None.

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EXPLANATORY NOTE

This Amendment No. 1 to Annual Report on Form 10-K/A amends our Annual Report on Form 10-K for the year ended December 31, 2009 filed with the Securities and Exchange Commission on March 31, 2010 (the “Original Report”). This Form 10-K/A replaces in its entirety the information previously incorporated by reference in Part III of the Original Report.

INDEX TO FORM 10-K/A

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PART III

Board of Directors

Our board of directors is divided into three classes. Each of the directors serves a three-year term, with one class of directors being elected by our stockholders at each annual meeting. Currently, our directors are divided into Classes I, II and III as follows:

Yang Zhao, Ph.D. is our founder and has served as our President and Chief Executive Officer since our inception and as chairman of the Board of Directors since 2007. Dr. Zhao has over 17 years of experience in MEMS technology and related business development. Prior to founding our company in 1999, Dr. Zhao served in various management positions at Analog Devices, Inc. for seven years, where he was instrumental in developing ADI’s MEMS product line and forming industry-wide strategic relationships. Dr. Zhao is well-recognized in the field of MEMS technology. He has been named as an inventor on 22 U.S. patents in IC circuit, processing, packaging and MEMS technology. Dr. Zhao holds a B.S. degree in physics from Peking University, as well as a master’s degree and a Ph.D. in electrical engineering from Princeton University where he studied under Professor Daniel Tsui, who won the 1998 Nobel Prize in physics. He is currently the vice chairman of the board at the School of Engineering of Peking University. We believe that Dr. Zhao’s educational background in electrical engineering and MEMS technology, his prior management experience and his extensive knowledge of our company’s history and culture, its products, technology and personnel, and its markets and customers, qualify him to serve as a member of our board of directors.

Roger W. Blethen has served as a director since 2005. In March 2008, our Board of Directors also designated Mr. Blethen as our lead director. In 2001, Mr. Blethen was appointed chairman of the board of LTX Corporation, a provider of semiconductor test solutions to major integrated-circuit manufacturers. Mr. Blethen served as the president and chief executive officer of LTX Corporation from 1994 to October 2005. Mr. Blethen serves as Chairman of Quebec-based Diablo Technologies Inc. Mr. Blethen currently serves Northeastern University on its Industrial Advisory Board to the Department of Electrical and Computer Engineering and as an advisor to its School for Technological Entrepreneurship. Mr. Blethen received his B.S. in Electrical Engineering from Northeastern University in 1974. We believe that Mr. Blethen’s educational background in electrical engineering, his broad knowledge of the semiconductor industry, gained from his long tenure as a senior operating executive and director of LTX Corporation and as a director of Diablo Technologies, and the skills, judgment and experience he has accumulated in these capacities and as a chief executive officer qualify him to serve as a member of our board of directors.

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Lawrence A. Kaufman, Ph.D. has served as a director since 2008. Dr. Kaufman has been the president and chief executive officer of Lightwave Power Inc., a provider of photovoltaic products for solar energy, since May 2008. From 2006 to 2007, Dr. Kaufman was a partner in The GulfStream Group. Prior to joining The GulfStream Group, Dr. Kaufman founded Sionex Corporation, a venture-backed company that develops miniature chemical sensors, and served as its president and chief executive officer from 2000 to 2003 and as Executive Vice President from 2003 to 2005. Dr. Kaufman currently serves as a director of Top Banana, a non-profit education company, a director of Sionex Corporation and is a partner in The Pinnacle Acquisition Group. Dr. Kaufman was a director of Optical Tape Systems, Inc., from 2005 to 2007, and a director of The MicroOptical Corporation, from 2002 to 2006. Dr. Kaufman received a Bachelor of Science degree in Physics from Rensselaer Polytechnic Institute and a Ph.D. in Solid State Physics from Tufts University. We believe that Dr. Kaufman’s educational background in solid state physics, his knowledge of many facets of the electronics industry, and his management experience gained from his employment as a senior operating executive and director of companies in a wide range of businesses qualify him to serve as a member of our board of directors.

Michael Tung has served as a director since 2004. Mr. Tung joined InveStar Capital Inc. as chief financial officer and Managing Partner in 2002 and is responsible for managing its investment portfolio companies in both Taiwan and U.S. Mr. Tung also serves as Managing Partner to manage the Silicon Valley office. Mr. Tung has over 20 years of experience in finance, taxation, accounting and general management. He served as chief financial officer for more than 10 years in various organizations, including Acer America Corp., Foxconn Corporation and Fibera Inc. (a start-up company). Mr. Tung worked as Senior Audit Manager of KPMG for 10 years. Mr. Tung received a B.S. degree in Accounting from Tam Kay University. We believe that Mr. Tung’s educational background in accounting and finance, his broad experience in finance, taxation, accounting and general management and his knowledge of our industry, gained from his employment as an executive of Investar Capital and as a chief financial officer of companies engaged in businesses similar to ours, qualify him to serve as a member of our board of directors.

David Yang has served as a director since 2007. Mr. Yang is a partner of The CID Group and joined The CID Group as one of the founding employees in 1998. Prior to founding The CID Group, Mr. Yang co-founded an incubator firm, Future Technology Consulting, Inc. to provide legal and advisory work to technology start-up companies in Taiwan. From 1994 to 1997, he served as a lawyer for Tsar and Tsai Law Firm and Jones Day. Mr. Yang has previously served as director or observer for Techwell, Inc., Advanced Analogic Technologies, Inc. and Young Fast Optoelectronic Co., Ltd. Mr. Yang received a J.D. degree from Cornell University in 1993 and a B.A. degree in Asian Studies from the University of Michigan, Ann Arbor in 1990. We believe that Mr. Yang’s professional training in law, his extensive experience in advising companies engaged in businesses similar to ours, his service as a director and board observer to such companies and his background as a private equity investor qualify him to serve as a member of our board of directors.

Paul M. Zavracky, Ph.D. has served as a director since 1999. Dr. Zavracky’s more than 30 years of business experience includes research at MIT Lincoln Laboratory, teaching at a major university, and management of successful venture funded companies. Since 2006 he has served Northeastern University as the Dean of the School of Technological Entrepreneurship. From 1998 to 2006, he was the president and chief operating officer of The MicroOptical Corporation, a start-up company he co-founded. Between 1991 and 1998, he was a tenured professor of electrical engineering at Northeastern University. Before joining Northeastern University, Dr. Zavracky was the chief operating officer of Kopin Corporation, a venture backed company that he and a small group of colleagues from the Massachusetts Institute of Technology’s Lincoln Labs started. He led the effort in establishing Kopin’s SOI materials capability as an enabling technology for liquid crystal microdisplays. Dr. Zavracky spent five years at The Foxboro Company as principal scientist and technical group leader establishing a MEMS program beginning in 1980. Dr. Zavracky also spent five years at Coulter Corporation managing the government system group working on electrophotographic film and five years at MIT Lincoln Laboratory where he was involved in the development of materials for solar energy applications. He obtained his Ph.D. in Physics at Tufts University. He holds Bachelors and Master’s degrees in Physics from Northeastern University. He has more than 100 publications and 67 issued patents. We believe that Dr. Zavracky’s educational background in physics, his distinguished academic background, his experience as an entrepreneur and his service in senior scientific and operating executive positions at a range of large and small companies in industries related to our own qualify him to serve as a member of our board of directors.

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Chairman of the Board and Lead Director

Yang Zhao, Ph.D., our president and chief executive officer, is also the chairman of our board of directors. In that capacity, he presides over all meetings of the board. In March 2008, our board of directors established the additional position of lead director and appointed Roger Blethen to serve in that position. Our lead director is a non-employee director whose responsibilities are to:

Audit committee. Our audit committee consists of Messrs. Tung, Yang and Zavracky, with Mr. Tung serving as chair. Our audit committee oversees our corporate accounting and financial reporting process and internal controls over financial reporting. Our audit committee evaluates the qualifications, independence and performance of our independent registered public accounting firm, Ernst & Young LLP; engages and determines the compensation of the independent auditor; approves the retention of the independent auditor to perform any proposed permissible non-audit services; reviews our financial disclosures, including our critical accounting policies and internal controls over financial reporting; prepares an annual report to our stockholders for inclusion in our proxy statement; reviews and approves in advance any proposed related party transactions; and discusses with management and the independent auditor the results of the annual audit and our financial statements. We believe that our audit committee members meet the requirements for independence and financial literacy under the current requirements of the Sarbanes-Oxley Act of 2002, The Nasdaq Global Market and SEC rules and regulations. In addition, the board of directors has determined that Mr. Tung is qualified as an “audit committee financial expert” within the meaning of the SEC rules and regulations. A copy of the charter of our audit committee is available in the Investor Relations section of our website at www.memsic.com.

2009 Director Compensation

Members of our board of directors receive cash retainers (payable quarterly in arrears), per meeting fees and annual stock option awards, as follows:

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The following table details the compensation paid to our directors, other than Dr. Zhao, for the year ended December 31, 2009.

Code of Conduct and Code of Ethics

Our board of directors has adopted a code of conduct, which establishes the standards of ethical conduct applicable to all of our directors, officers and employees. Our code of conduct addresses issues relating to, among other things, conflicts of interest, related party transactions, use of company funds and sensitive payments, corporate opportunities, internal controls over financial reporting, and confidential information. In addition, our board of directors has adopted a code of ethics applicable to our chief executive officer and chief financial officer. Our code of ethics sets guidelines for these individuals to implement policies and procedures to enhance disclosure and reporting system at our company. Our code of conduct is publicly available on our website at http://www.memsic.com. Any waiver of our code of conduct or code of ethics with respect to our chief executive officer, chief financial officer, controller or persons performing similar functions may only be authorized by our audit committee and will be disclosed as required by applicable law.

Section 16(a) Beneficial Ownership Reporting Compliance

Section 16(a) of the Securities Exchange Act of 1934 requires our directors and executive officers, and persons who beneficially own more than ten percent of a registered class of our equity securities, to file reports of ownership of, and transactions in, our securities with the Securities and Exchange Commission. These directors, executive officers and ten-percent stockholders are also required to furnish us with copies of all Section 16(a) forms they file.

Based solely on a review of the copies of such forms received by us, and on written representations from certain reporting persons, we believe that during 2009 our directors, officers and ten-percent stockholders complied with all applicable Section 16(a) filing requirements.

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Executive Officers

The following table sets forth information with respect to our executive officers as of April 28, 2010:

Further information regarding Dr. Zhao is available under the section titled “–Board of Directors.”

Patricia Niu has served as our Chief Financial Officer since June 2008. From 2003 to 2008, Ms. Niu held positions as our Vice President of Finance and Corporate Controller. Ms. Niu has over 15 years of experience in corporate finance and four years of experience in commercial banking. Prior to joining MEMSIC, Ms. Niu served as the International Business Unit Controller at Key3Media Events, Inc. from 2001 to 2002 and Audit Supervisor and Senior Financial Analyst at Fresenius Medical Care, N.A. from 1995 to 2001. From 1989 through 1995, Ms. Niu was a commercial lender at Bank of China, Head Office in Beijing, China and The Savings Bank in Wakefield, Massachusetts. Ms. Niu received an M.B.A. from Northeastern University in Boston in 1994 and a B.A. from Beijing Foreign Studies University in China in 1989.

Mark S. Laich has served as our Vice President of Worldwide Sales since October 2008. Mr. Laich has over 21 years experience in semiconductor sales and intellectual property licensing. From October 2004 to December 2007, Mr. Laich held various senior sales management positions with Potentia Semiconductor Corporation. Prior to Potentia Semiconductor, from March 2001 to September 2004, Mr. Laich was director of sales at Azanda Network Devices, Inc. Mr. Laich received a Bachelor of Science in Electrical Engineering from Virginia Polytechnic Institute.

2009 Summary Compensation Table. The following table sets forth compensation information for our chief executive officer and our two other most highly compensated executive officers who were in office at December 31, 2009. These persons are referred to as our “named executive officers” elsewhere in this Report. Except as provided below, none of our named executive officers received any other compensation required to be disclosed by law or in excess of $10,000 annually.

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Outstanding Equity Awards at December 31, 2009. The following table provides information concerning outstanding equity awards held by each of our named executive officers as of December 31, 2009.

Employment Arrangements with Named Executive Officers

Change in Control Agreements. On March 26, 2009, we entered into Senior Executive Change in Control Agreements, or the Change in Control Agreements, with Yang Zhao and Patricia Niu. These agreements provide for the acceleration of vesting of stock options held by Dr. Zhao and Ms. Niu if, after a change in control, we terminate the executive’s employment without cause or the executive terminates his or her employment due to a breach by us (as each event is defined in the Change in Control Agreements). Once the acceleration provisions of the Change in Control Agreements are triggered, the vesting of each option held by the executive shall be accelerated such that a

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portion of such options equal to the portion that would otherwise have vested during the last year of the vesting schedule shall become exercisable immediately. This acceleration shall be applied after, and not in lieu of, any accelerated vesting that may be provided for under the terms of such option and any plan under which such option was granted and by any resolution of our board of directors or any committee thereof. However, to the extent that the total acceleration of vesting that each executive would receive exceeds a combined total of twenty-four (24) months then the provisions of these Change in Control Agreements shall not apply.

Stock Owned by Directors, Executive Officers and Greater-Than-5% Stockholders

The following table sets forth certain information with respect to beneficial ownership of our common stock, as of April 28, 2010, by:

Beneficial ownership is determined in accordance with Rule 13d-3 under the Exchange Act and is based on 23,804,863 shares of our common stock outstanding as of April 28, 2010. Amounts under the heading “Right to Acquire” represent shares that may be acquired upon exercise of stock options that are currently exercisable or exercisable within 60 days of April 28, 2010. For purposes of calculating percentages in the table below, shares listed opposite the name of a person under the heading “Right to Acquire” are deemed outstanding and beneficially owned by such person, but are not deemed outstanding for computing the percentage ownership of any other person. To our knowledge, except as set forth in the footnotes to this table and subject to applicable community property laws, each person named in the table has sole voting and investment power with respect to the shares set forth opposite such person’s name. Except as otherwise indicated, the address of each of the persons in this table is c/o MEMSIC, Inc., One Tech Drive, Andover, Massachusetts 01810.

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Equity Compensation Plan Information

We have one equity compensation plan under which shares are currently authorized for issuance, our 2007 Stock Incentive Plan. In addition, we have one equity compensation plan under which awards are currently outstanding but pursuant to which no future awards may be granted, our 2000 Omnibus Stock Plan. Both of our equity compensation plans were approved by our stockholders prior to our initial public offering in December 2007. The following table provides information regarding securities authorized for issuance as of December 31, 2009 under our equity compensation plans.

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Director Independence

A majority of our directors are independent within the meaning of the applicable rules of the SEC and The Nasdaq Stock Market, LLC. Specifically, our board of directors has determined that each of Messrs. Blethen, Kaufman, Tung, Yang and Zavracky is an independent director.

Policies and Procedures Regarding Related Party Transactions

Our policies and procedures for related party transactions are contained in our code of conduct and our audit committee charter.

Our code of conduct requires all of our employees, officers and directors to report to our chief executive officer any significant related-party transaction that he or she believes exits or might occur. These related-party transactions include those between our company and: (i) family members or friends of an employee, officer or director; (ii) an organization for which the employee, officer or director currently or has in the past five years served as an officer, director, trustee or partner; (iii) an organization in which the employee, officer or director has a financial interest, other than an investment of less than 1% of the outstanding shares of a publicly-held company; and (iv) any individual or organization with whom the employee, officer or director is negotiating, or with whom he or she has an arrangement, concerning prospective employment.

Our audit committee charter provides the committee with the responsibility to review, and the authority to approve or disapprove, any transaction between our company and any (i) of our directors or executive officers; (ii) nominee for election as a director; (iii) person known to our company to own more than 5% of any class of our voting securities; (iv) member of the immediate family of any such person, if such transaction is required to be disclosed under the related-party transactions rules of the SEC.

In addition to the compensation arrangements with directors and the executive officers described above, the following is a description of each transaction during fiscal year 2009 and each currently proposed transaction in which:

Relationship with InveStar Funds and Taiwan Semiconductor Manufacturing Company, Limited, or TSMC

InveStar Semiconductor Development Fund, Inc. and InveStar Semiconductor Development Fund, Inc. (II) LCD, together the “InveStar Funds,” hold in aggregate approximately 10.6% of our common stock on a fully diluted basis. TSMC, our largest third-party supplier, has historically supplied substantially all of our wafers required in our manufacturing process. In 2009, we purchased an aggregate of $4.9 million in wafers from TSMC. TSMC holds in the aggregate 97% interest in the Investar Funds and is authorized to appoint the board of directors of the InveStar Funds. InveStar Capital, Inc. is the fund manager and holds the remaining interest in the InveStar Funds. One of our directors, Michael Tung, is the managing partner and chief financial officer of InveStar Capital, Inc.

Fees for Professional Services

The following is a summary of the fees for professional services rendered by Ernst & Young LLP for 2009 and 2008:

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Audit fees. Audit fees represent fees for professional services performed by Ernst & Young LLP for the audit of our annual financial statements and the review of our quarterly financial statements, as well as services that are normally provided in connection with statutory and regulatory filings or engagements and related expenses.

Audit-related fees. Audit-related fees represent fees for assurance and related services performed by Ernst & Young LLP that are reasonably related to the performance of the audit or review of our financial statements, including consultation on accounting standards or accounting for specific transactions.

Tax fees. Tax fees represent fees for professional services performed by Ernst & Young LLP with respect to tax compliance, tax advice and tax planning and related expenses. These services include assistance with the preparation of federal, state, and foreign income tax returns.

All other fees. All other fees represent fees for products and services provided by Ernst & Young LLP, other than those disclosed above.

Pre-Approval Policies and Procedures

Our audit committee’s pre-approval policies or procedures do not allow our management to engage Ernst & Young LLP to provide audit, audit-related or non-audit related services without audit committee pre-approval. All of the services provided by Ernst & Young LLP during 2009 and 2008 were pre-approved.

PART IV

(a) (3) Exhibits

The following exhibits are included in this Amendment No. 1 to our Annual Report on Form 10-K:

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SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this Amendment No. 1 to Annual Report on Form 10-K to be signed on its behalf by the undersigned, thereunto duly authorized, as of April 30, 2010.

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