**Exhibit      12.1**

| **Ameren                Corporation****Computation                of Ratio of Earnings to Fixed Charges****(Thousands                of Dollars, Except Ratios)** |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                              |   |   |   |   |
|                                                                                                                                                              | **Nine                Months** |   | **Year** |   |
|                                                                                                                                                              | **Ended** |   | **Ended** |   |
|                                                                                                                                                              | **September                30,** |   | **December                31,** |   |
|                                                                                                                                                              | **2006** |   | **2005** |   |
| Net                income from continuing operations                                                                                                              | $ | 485,730 |   | $ | 605,725 |   |
| Less-                Change in accounting principle                                                                                                               |   | - |   |   | (22,135 | ) |
| Less-                Minority interest                                                                                                                            |   | (23,329 | ) |   | (3,231 | ) |
| Add-                Taxes based on income                                                                                                                         |   | 272,939 |   |   | 356,016 |   |
| Net                income before income taxes, change in accountingprinciple,                and minority interest                                                |   | 781,998 |   |   | 987,107 |   |
|                                                                                                                                                              |   |   |   |   |   |   |
| Add-                fixed charges:                                                                                                                                |   |   |   |   |   |   |
| Interest                on long term debt                                                                                                                         |   | 234,781 |   |   | 297,822 |   |
| Estimated                interest cost within rental expense                                                                                                      |   | 2,878 |   |   | 4,208 |   |
| Amortization                of net debt premium, discount,and                expenses                                                                             |   | 11,511 |   |   | 14,687 |   |
| Subsidiary                preferred stock dividends                                                                                                               |   | 8,019 |   |   | 12,745 |   |
| Adjust                preferred stock dividends to pre-taxbasis                                                                                                   |   | 4,433 |   |   | 7,227 |   |
| Total                fixed charges                                                                                                                                |   | 261,622 |   |   | 336,689 |   |
| Less:                Adjustment of preferred stock dividends topre-tax                basis                                                                       |   | 4,433 |   |   | 7,227 |   |
|                                                                                                                                                              |   |   |   |   |   |   |
| Earnings                available for fixed charges                                                                                                               |   | 1,039,187 |   |   | 1,316,569 |   |
|                                                                                                                                                              |   |   |   |   |   |   |
| Ratio                of earnings to fixed charges                                                                                                                 |   | 3.97 |   |   | 3.91 |   |
|                                                                                                                                                              |   |   |   |   |   |   |