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UNITED STATES
SECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549

FORM 20-F/A

(Amendment No. 1)

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

For the fiscal year ended December 31, 2005

Commission file number: 0-28578

DASSAULT SYSTEMES

(Exact name of Registrant as specified in its charter)

France(Jurisdiction of Incorporation or Organization)

9, quai Marcel Dassault 
B.P. 310, 92156 Suresnes Cedex, France 
(33-1) 40-99-40-99(Address of Principal Executive Offices)

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                                
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | -----------------------------------------------------------------------------------------
|                                                                                                                                                                           |  |                                                                                          
|American
        Depositary Shares, each representing one common share, nominal value €
        1 per share
      
      Common stock, nominal
        value € 1 per share |  | The
        Nasdaq National Market
      
      
      The Nasdaq National
        Market

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

None.

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

None.

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.

Common Stock, nominal value €1 per share as of December 31, 2005:  115,038,378

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

|Yes |  | 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 | 
|--- |  | -- | 

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 |  | 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 |  | Accelerated filer |  | Non-accelerated filer | 
|----------------------- |  | ----------------- |  | --------------------- | 

Indicate by check mark which financial statement item the Registrant has elected to follow.

|Item 17 |  | Item 18 | 
|------- |  | ------- | 

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).



|Yes |  | No | 
|--- |  | -- | 



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EXPLANATORY NOTE

This Amendment No. 1 on Form 20-F/A (Amendment No. 1) to our Annual Report on Form 20-F for the fiscal year ended December 31, 2005, filed on June 29, 2006, is being filed solely for the purpose of amending the exhibits to include Exhibits 4(a).5 and 4(a).6.  Due to a filing error, these exhibits were not included in the initial filing of the Form 20-F.

This Amendment
  No. 1 speaks as of the filing date of our annual report on Form 20-F for
  the fiscal year ended December 31, 2005, filed on June 29, 2006. Other
  than for the purpose of filing Exhibits 4(a).5 and 4(a).6, this Amendment No. 1
  does not, and does not purport to, amend, update or restate the information
  in any other item of the annual report on Form 20-F filed on June 29, 2006.





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SIGNATURES



The registrant hereby certifies that it meets all of the requirements for filing this Form 20-F/A and that it has duly caused and authorized the undersigned to sign this Amendment No. 1 to its annual report on its behalf.





|Date: June
        30, 2006 | DASSAULT
        SYSTEMES S.A.                              
|--------------------------- | ------------------------------------------------------------
|                            |                                                             
|                            | /s/Thibault
        de Tersant                              
|                            | Thibault
        de Tersant                                 
|                            | Executive
        Vice President and Chief Financial Officer