**Exhibit12.1**

**SOUTHERNCOPPER CORPORATION**

**COMPUTATIONOF FINANCIAL RATIOS**

**(Inmillions except ratios)**
| **EARNINGS TO FIXED CHARGES**                                                    | ** ** | ** ** | ** ** | **2006** | ** ** | **2005** | ** ** | **2004** | ** ** | **2003** | ** ** | **2002** | ** ** |
|-------------------------------------------------------------------------------------------------|------------|------------|------------|----------|------------|----------|------------|----------|------------|----------|------------|----------|------------|
| Earnings before tax,  minority interest and cumulative effect of change in accounting principle |       | $          | 3,006.0    |     | $          | 2,002.4  |       | $        | 1,420.9    |     | $          | 209.5    |       | $ | 65.3 |   |
| Fixed charges                                                                                   |       |       |       |     |       |     |       |     |       |     |       |
| Interest expense                                                                                |       | 113.4      |       | 108.9    |       | 106.5    |       | 117.0    |       | 128.7    |       |
| (Gain) loss on debt  prepayment                                                                 |       | 1.1        |       | 10.6     |       | 16.5     |       | 5.8      |       | 12.4     |       |
| Total fixed charges                                                                             |       | 114.5      |       | 119.5    |       | 123.0    |       | 122.8    |       | 141.1    |       |
|                                                                                            |       |       |       |     |       |     |       |     |       |     |       |
| Earning plus fixed  charges                                                                     |       | $          | 3,120.5    |     | $          | 2,121.9  |       | $        | 1,543.9    |     | $          | 332.3    |       | $ | 206.4 |   |
|                                                                                            |       |       |       |     |       |     |       |     |       |     |       |
| **Earnings to fixed charges**                                                                   | ** ** | **27.2**   | ** ** | **17.8** | ** ** | **12.6** | ** ** | **2.7**  | ** ** | **1.5**  | ** ** |

 
| ** **                              | ** ** | **2006** | ** ** | **2005** | ** ** | **2004** | ** ** | **2003** | ** ** | **2002** | ** ** |
|-----------------------------------------|------------|----------|------------|----------|------------|----------|------------|----------|------------|----------|------------|
| Total debt                              |       | $        | 1,528.1    |     | $          | 1,172.1  |       | $        | 1,330.3    |     | $          | 1,671.2 |   | $ | 1,621.2 |   |
| Cash and marketable securities  balance |       | (1,302.8 | )          | (876.0   | )          | (756.0   | )          | (351.6   | )          | (175.1   | )          |
| Net debt (A)                            |       | 225.3    |       | 296.1    |       | 574.3    |       | 1,319.6  |       | 1,446.1  |       |
|                                    |       |     |       |     |       |     |       |     |       |     |       |
| Total capitalization                    |       |     |       |     |       |     |       |     |       |     |       |
| Net debt (A)                            |       | 225.3    |       | 296.1    |       | 574.3    |       | 1,319.6  |       | 1,446.1  |       |
| Stockholders’ equity               |       | 3,666.6  |       | 3,326.1  |       | 2,813.6  |       | 2,022.7  |       | 1,881.5  |       |
| Total B                                 |       | $        | 3,891.9    |     | $          | 3,622.2  |       | $        | 3,387.9    |     | $          | 3,342.3 |   | $ | 3,327.6 |   |
|                                    |       |     |       |     |       |     |       |     |       |     |       |
| **Net debt/total capitalization**       | ** ** | **5.8**  | **%**      | **8.2**  | **%**      | **17.0** | **%**      | **39.5** | **%**      | **43.5** | **%**      |

 

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