Abstract: It is selected some of the mining enterprises and non-mining enterprises listed samples randomly, then used effective tax rate to analyze them and found that the weighted average effective income tax rate of mining companies is lower 14.7 percent than that of non-mining enterprises and the arithmetic weighted average effective tax rate low 26.4 %. When used probability investment risk model to calculate tax and found that return of investment risk factor significantly influence the effective tax rate. Identifying industry the investment risk rate can quantitatively evaluate tax burden reasonable.