**                                    Registration No.333-109182 424(b)(3)**

**                                     PricingSupplement No:391 Cusip:14912L2E0**

**                                    Dated:  August 17, 2004    **

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***Caterpillar Financial Services Corporation***

***Medium-Term Notes, Series F***

***(Floating Rate)***

***    With Maturities of 9 Months or More from Date of Issue***

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**Principal Amount:       Initial Interest Rate:        Proceed Amount:**

**$350,000,000          1.80% including the spread       $349,482,000**

**                                         **

**Original Issue Date:         Commission Fee:          Maturity Date:**

**08/20/2004                    $518,000                 08/20/2007**

**               **

**Dealer:             Index Maturity             Spread +/-:**

**Barclays Capital Inc   $175 mm    Quarterly                   +7**

**(DTC #7256)**

**Goldman Sachs & Co.   $175 mm**

**(DTC #0005)**

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**Specified Currency:     Option to Elect Payment       Authorized Denominations**

**x****U.S. dollars          in U.S. dollars               (only applicableif**

**_ Other:___________     (only applicable if           Specified Currency is**

**                        Specified Currency is         other thanU.S.**

**                        other than U.S. dollars):     N/A    **

**                          N/A                              **

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**The Note isa:                                        Exchange RateAgent          X GlobalNote                                     (if other thanU.S.   **

**        CertificatedNote                                Bank Trust, N.A.): N/A         (onlyapplicable if**

**       SpecifiedCurrency                               **

**       is other than U.S. dollars)             Spread Multiplier:N/A                                                                           **

**Interest Rate Basis or Bases: 3 Month LIBOR + 7 BPS**

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**LIBOR Source (only applicable if LIBOR Interest Rate Basis):**

**__Reuters       X Telerate**

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**LIBOR Currency (only applicable if LIBOR Interest Rate Basis): U.S. Dollar**

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**Maximum Interest Rate:  N/A            Interest Payment Period: Quarterly**

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**Interest Payment Dates: Coupons will pay/reset on the 20th of November,  **

**            February, May and August (or next good Business**

**            Day) modified following convention.**

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***Initial payment due:  11/20/04.***

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**Minimum Interest Rate: N/A**

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**Interest Rate Reset Option: _Yes X No**

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**Optional Reset Dates (only applicable if option to reset spread or spread multiplier): N/A**

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**Basis for Interest Rate Reset (only applicable if option to reset spread or spread multiplier): N/A**

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**Minimum Interest Rate: N/A            Interest Payment Dates: N/A**

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**Stated Maturity Extension Option: _ Yes X No**

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**Extension Period(s) and Final Maturity Date (only applicable if option to extend stated maturity): N/A**

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**Basis for Interest Rate During Extension Period (only applicable if option to extend stated maturity): N/A**

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**Historical Exchange Rate (only applicable if Specified Currency other than U.S. dollars): N/A**

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**Interest Payment Dates: Coupons will pay/reset on the 20th of November,**

**            February, May and August (or next good Business**

**            Day) modified following convention.**

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***Initial payment due:  11/20/04.***

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**Interest Determination Dates: Two London business days prior to the reset date.**

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**Calculation Agent (if other than U.S. Bank Trust, N.A.): N/A**

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**Original Issue           Total Amount of OID: N/A    Terms of Amortizing     Discount Note:                                       Notes:  N/A**

** ****  Yes      x No          Issue Price(expressed                **

**                         as a percentage of   **

**                         aggregate principal**

**                         amount): 100%**

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**Redemption Date(s) (including                        Redemption Price(s): N/A any applicable regularor                            **

**special record dates): N/A**

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**Repayment Date(s) (including                         Repayment Price(s): N/A any applicable regularor**

**special record dates): N/A**

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**Other Terms: N/A**

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**     The interest rates on the Notes may be changed by Caterpillar Financial Services Corporation from time to time, but any such change will not affect the interest rate on any Note offered prior to theeffective date of the change.  Prior to the date of this Pricing Supplement, $2,645.00 mm principal amount of the Notes had been sold at interest rates then in effect.**

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**    Pricing Supplement to Prospectus Supplement dated November 06, 2003**

**        and Prospectus dated October 15, 2003**