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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 20-F/A

(Amendment No. 2)



| ̈ | REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ----------------------------------------------------------------------------------------------

OR

|x | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ------------------------------------------------------------------------------------

For the fiscal year ended March 31, 2011

OR

| ̈ | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ----------------------------------------------------------------------------------------

OR

| ̈ | SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | -------------------------------------------------------------------------------------------

Commission file number: 333-13896

Nihon Densan Kabushiki Kaisha

(Exact name of Registrant as specified in
its charter)

NIDEC CORPORATION

(Translation of Registrants name into English)



|                                                |  |                                                       
|----------------------------------------------- |  | ------------------------------------------------------
|Japan                                           |  | 338 Kuzetonoshiro-cho, Minami-ku, Kyoto 601-8205 Japan
|(Jurisdiction of incorporation or organization) |  | (Address of principal executive offices)              



| |  |                                                                                         |  | 
| |  | --------------------------------------------------------------------------------------- |  | 
| |  | Masahiro Nagayasu, +81-75-935-6140,
ir@jp.nidec.com, address is same as above           |  | 
| |  | (Name, Telephone, E-mail and/or Facsimile number and Address of Company Contact Person) |  | 

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



|                                                                                                   |  |                                                  
|-------------------------------------------------------------------------------------------------- |  | -------------------------------------------------
|Title of each class                                                                                |  | Name of each exchange on which registered        
|Common Stock* American Depositary Shares each representing
one-fourth of one share of common stock |  | New York Stock Exchange
  New York Stock Exchange

Securities registered or to be registered pursuant to Section 12(g) of the Act:

None

(Title of Class)

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act:

None

(Title of Class)

Indicate the number of outstanding shares of each of the issuers classes of capital or common stock as of the close of the period covered by the
annual report.

As of March 31, 2011, 145,075,080 shares of common stock were outstanding, including 2,324,735 shares represented by
9,298,940 American Depositary Shares and 6,593,647 shares held in treasury.

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

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or
15(d) of the Securities Exchange Act of 1934.    Yes   ̈    No  x

Note - Checking the box above will not relieve any registrant required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange
Act of 1934 from their obligations under those Sections.



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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 (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such
files).    Yes  x    No   ̈

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of accelerated filer and large accelerated filer in
Rule 12b-2 of the Exchange Act. (Check one):



|                           |  |                      |  |                         
|-------------------------- |  | -------------------- |  | ------------------------
|Large accelerated filer  x |  | Accelerated filer   ̈ |  | Non-accelerated filer   ̈

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in
this filing:



|             |  |                                                                                                          |  |         
|------------ |  | -------------------------------------------------------------------------------------------------------- |  | --------
|U.S. GAAP  x |  | International Financial Reporting Standards as
issued by the International Accounting Standards Board   ̈ |  | Other   ̈

If Other has been checked in response to the previous question, indicate by check mark which financial
statement item the registrant has elected to follow.    Item 17   ̈    Item 18   ̈

If this is an annual report, indicated by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange
Act).    Yes   ̈    No  x

* Not for trading, but only in connection with the listing of the American Depositary Shares.









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Explanatory Note



This Amendment No. 2 to Form 20-F (the "Amendment No. 2") amends our annual report on Form 20-F for the fiscal year ended March 31, 2011, originally filed with the U.S. Securities and Exchange Commission on June 23, 2011 (the "Form 20-F"), and subsequently amended on June 28, 2011 to provide Interactive Data File disclosure as Exhibit 101 in accordance with Rule 405 of Regulation S-T.  The purpose of this Amendment No. 2 is to correct a clerical error contained in the report of independent registered public accounting firm set forth on pages F-2 and F-3.



No other changes have been made to the Form 20-F. The Form 20-F, as amended by this Amendment No. 2, does not reflect events that may have occurred subsequent to the original filing date of the Form 20-F, and does not modify or update in any way the disclosures made in the Form 20-F other than as specifically discussed above.









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Item 19. Exhibits.



|Exhibit Number | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|-------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|1.1            | Articles of Incorporation of Nidec Corporation (English translation)
(Incorporated by reference to Nidecs annual report on Form 20-F for the year ended March 31, 2010 filed on June 24, 2010)                                                                                                                                                                                                                                                                 
|1.2            | Share Handling Regulations of Nidec Corporation (English translation)
(Incorporated by reference to Nidecs annual report on Form 20-F for the year ended March 31, 2009 filed on June 25, 2009)                                                                                                                                                                                                                                                                
|1.3            | Regulations of the Board of Directors of Nidec Corporation (English translation)
(Incorporated by reference to Nidecs annual report on Form 20-F/A for the year ended March 31, 2008 filed on December 24, 2008)                                                                                                                                                                                                                                               
|1.4            | Regulations of the Board of Corporate Auditors of Nidec Corporation (English translation)
(Incorporated by reference to Nidecs annual report on Form 20-F/A for the year ended March 31, 2008 filed on December 24, 2008)                                                                                                                                                                                                                                      
|2.1            | Form of Deposit Agreement among Nidec Corporation, JP Morgan Chase Bank, N.A. (formerly, Morgan Guaranty Trust Company of New York) as Depositary and all owners and holders from time to time of American Depositary Receipts
(Incorporated by reference to the Registration Statement on Form F-6 (file no. 333-13896) filed on September 7, 2001, as amended by Post-Effective Amendment No.1 to the Registration Statement on Form F-6 on December 12, 2003)
|2.2            | Form of American Depositary Receipt
(Incorporated by reference to the Registration Statement on Form F-6 (file no. 333-143706) filed on June 13, 2007)                                                                                                                                                                                                                                                                                                          
|4.1            | Loan Agreement, dated December 3, 2008, between Nidec Corporation and S.N. Kohsan (English translation)
(Incorporated by reference to Nidecs annual report on Form 20-F for the year ended March 31, 2009 filed on June 25, 2009)                                                                                                                                                                                                                              
|4.2            | Share Exchange Agreement, dated April 26, 2010 between Nidec Corporation and Nidec Servo Corporation
(Incorporated by reference to Nidecs annual report on Form 20-F for the year ended March 31, 2010 filed on June 24, 2010)                                                                                                                                                                                                                                 
|8.1            | Subsidiaries of Nidec Corporation
(Previously filed with Nidecs annual report on Form 20-F for the year ended March 31, 2011, filed on June 23, 2011)                                                                                                                                                                                                                                                                                                          
|11.1           | Compliance Code of Conduct (English translation)
(Previously filed with Nidecs annual report on Form 20-F for the year ended March 31, 2011, filed on June 23, 2011)                                                                                                                                                                                                                                                                                           
|12.1           | Certification of the Chief Executive Officer required by Rule 13a-14(a)
(Filed herewith)                                                                                                                                                                                                                                                                                                                                                                        
|12.2           | Certification of the Chief Financial Officer required by Rule 13a-14(a)
(Filed herewith)                                                                                                                                                                                                                                                                                                                                                                        
|13.1           | Certification of the Chief Executive Officer required by Rule 13a-14(b) and Section 1350 of Chapter 63 of Title 18 of the United States Code
(Filed herewith)                                                                                                                                                                                                                                                                                                   
|13.2           | Certification of the Chief Financial Officer required by Rule 13a-14(b) and Section 1350 of Chapter 63 of Title 18 of the United States Code
(Filed herewith)                                                                                                                                                                                                                                                                                                   
|101.INS        | XBRL Instance Document
(Previously filed with Amendment No.1 to Nidecs annual report on Form 20-F for the year ended March 31, 2011, filed on June 28, 2011)                                                                                                                                                                                                                                                                                                   
|101.SCH        | XBRL Taxonomy Extension Schema
(Previously filed with Amendment No.1 to Nidecs annual report on Form 20-F for the year ended March 31, 2011, filed on June 28, 2011)                                                                                                                                                                                                                                                                                           
|101.CAL        | XBRL Taxonomy Extension Calculation Linkbase
(Previously filed with Amendment No.1 to Nidecs annual report on Form 20-F for the year ended March 31, 2011, filed on June 28, 2011)                                                                                                                                                                                                                                                                             
|101.DEF        | XBRL Taxonomy Extension Definition Linkbase
(Previously filed with Amendment No.1 to Nidecs annual report on Form 20-F for the year ended March 31, 2011, filed on June 28, 2011)                                                                                                                                                                                                                                                                              
|101.LAB        | XBRL Taxonomy Extension Label Linkbase
(Previously filed with Amendment No.1 to Nidecs annual report on Form 20-F for the year ended March 31, 2011, filed on June 28, 2011)                                                                                                                                                                                                                                                                                   
|101.PRE        | XBRL Taxonomy Extension Presentation Linkbase
(Previously filed with Amendment No.1 to Nidecs annual report on Form 20-F for the year ended March 31, 2011, filed on June 28, 2011)                                                                                                                                                                                                                                                                            



We have not included as exhibits certain instruments with respect to our long-term debt, the amount of debt authorized under each of which does not exceed 10% of our total assets, and we agree to furnish a copy of any such instrument to the Securities and Exchange Commission upon request.







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SIGNATURES





The registrant hereby certifies that it meets all of the requirements for filing on Form 20-F and that it has duly caused and authorized the undersigned to sign this amendment to the annual report on its behalf.





|NIDEC CORPORATION
|-----------------
|                 
|By:              
|Name:            
|Title:           

Date: June 30, 2011



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Report of Independent Registered Public Accounting Firm

To the Shareholders and Board of Directors of

Nihon Densan Kabushiki Kaisha

(NIDEC Corporation):

In our opinion, the accompanying consolidated balance sheets and the related consolidated statements of income, changes in equity, and
cash flows present fairly, in all material respects, the financial position of NIDEC Corporation and its subsidiaries (The Company) at March 31, 2011 and 2010, and the results of their operations and their cash flows for each of the
three years in the period ended March 31, 2011 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over
financial reporting as of March 31, 2011, based on criteria established in Internal ControlIntegrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). The Companys management is
responsible for these financial statements, for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in Managements Report on
Internal Control over Financial Reporting appearing under Item 15. Our responsibility is to express opinions on these financial statements and on the Companys internal control over financial reporting based on our integrated audits. We
conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the financial statements
are free of material misstatement and whether effective internal control over financial reporting was maintained in all material respects. Our audits of the financial statements included examining, on a test basis, evidence supporting the amounts
and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. Our audit of internal control over financial reporting
included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk.
Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions.

A companys internal control over financial reporting is a process designed to provide reasonable assurance regarding the
reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A companys internal control over financial reporting includes those policies and
procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are
recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management
and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the companys assets that could have a material effect on the financial
statements.



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Because of its inherent limitations, internal control over financial reporting may not
prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies
or procedures may deteriorate.

As described in Managements Report on Internal Control over Financial Reporting
appearing under Item 15, management has excluded Emerson Electric Co.s motors and control business from its assessment of internal control over financial reporting as of March 31, 2011 because it was acquired by the Company in a
purchase business combination on September 30, 2010. We have also excluded the Emerson Electric Co.s motors and control business from our audit of internal control over financial reporting. Emerson Electric Co.s motors and control
business is a wholly-owned business whose total assets and net sales represent 9.9% and 5.2%, respectively, of the related consolidated financial statement amounts as of and for the year ended March 31, 2011.

/s/ Kyoto Audit Corporation

Kyoto, Japan

June 22, 2011



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