Exhibit 12.1

Ameren Corporation

Computation of Ratio of Earnings to Fixed Charges

(Thousands of Dollars, Except Ratios)



|                                                                                     |  |                         |           |   |      |   |           |      |  |   |           |   |  |      |           |     |  |   |           |    
|------------------------------------------------------------------------------------ |  | ----------------------- | --------- | - | ---- | - | --------- | ---- |  | - | --------- | - |  | ---- | --------- | --- |  | - | --------- | ---
|                                                                                     |  | Year Ended December 31, |          
|                                                                                     |  | 2004                    |           |   | 2005 |   |           | 2006 |  |   | 2007      |   |  | 2008 |          
|Net income from continuing operations                                                |  | $                       | 529,884   |   |      | $ | 605,725   |      |  | $ | 546,738   |   |  | $    | 617,804   |     |  | $ | 605,189   |    
|Less- Change in accounting principle                                                 |  |                         |          |   |      |   | (22,135   | )    |  |   |          |   |  |      |          |     |  |   |          |    
|Less- Minority interest                                                              |  |                         | (4,201    | ) |      |   | (3,231    | )    |  |   | (27,135   | ) |  |      | (27,266   | )   |  |   | (28,422   | )  
|Add- Taxes based on income                                                           |  |                         | 282,558   |   |      |   | 356,016   |      |  |   | 283,825   |   |  |      | 330,141   |     |  |   | 326,736   |    
|                                                                                     |  |                         |           |   |      |   |           |      |  |   |           |   |  |      |           |     |  |   |           |    
|Net income before income taxes, change in accounting principle and minority interest |  |                         | 816,643   |   |      |   | 987,107   |      |  |   | 857,698   |   |  |      | 975,211   |     |  |   | 960,347   |    
|Add- fixed charges:                                                                  |  |                         |           |   |      |   |           |      |  |   |           |   |  |      |           |     |  |   |           |    
|Interest on long term debt                                                           |  |                         | 269,868   |   |      |   | 297,822   |      |  |   | 345,410   |   |  |      | 421,406   | (1) |  |   | 440,507   | (1)
|Estimated interest cost within rental expense                                        |  |                         | 3,185     |   |      |   | 4,208     |      |  |   | 4,081     |   |  |      | 5,020     |     |  |   | 6,510     |    
|Amortization of net debt premium, discount, and expenses                             |  |                         | 12,983    |   |      |   | 14,687    |      |  |   | 15,341    |   |  |      | 18,638    |     |  |   | 19,716    |    
|Subsidiary preferred stock dividends                                                 |  |                         | 11,089    |   |      |   | 12,745    |      |  |   | 10,936    |   |  |      | 10,871    |     |  |   | 10,357    |    
|Adjust preferred stock dividends to pre-tax basis                                    |  |                         | 5,913     |   |      |   | 7,227     |      |  |   | 5,565     |   |  |      | 5,709     |     |  |   | 5,497     |    
|                                                                                     |  |                         |           |   |      |   |           |      |  |   |           |   |  |      |           |     |  |   |           |    
|Total fixed charges                                                                  |  |                         | 303,038   |   |      |   | 336,689   |      |  |   | 381,333   |   |  |      | 461,644   |     |  |   | 482,587   |    
|                                                                                     |  |                         |           |   |      |   |           |      |  |   |           |   |  |      |           |     |  |   |           |    
|Less: Adjustment of preferred stock dividends to pre-tax basis                       |  |                         | 5,913     |   |      |   | 7,227     |      |  |   | 5,565     |   |  |      | 5,709     |     |  |   | 5,497     |    
|                                                                                     |  |                         |           |   |      |   |           |      |  |   |           |   |  |      |           |     |  |   |           |    
|Earnings available for fixed charges                                                 |  | $                       | 1,113,768 |   |      | $ | 1,316,569 |      |  | $ | 1,233,466 |   |  | $    | 1,431,146 |     |  | $ | 1,437,437 |    
|                                                                                     |  |                         |           |   |      |   |           |      |  |   |           |   |  |      |           |     |  |   |           |    
|Ratio of earnings to fixed charges                                                   |  |                         | 3.67      |   |      |   | 3.91      |      |  |   | 3.23      |   |  |      | 3.10      |     |  |   | 2.97      |    
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(1)Includes FIN 48 interest expense