In order to study the influence of different rainfall intensity on the erosion, artificial rainfall simulation experiment and indoor analysis were connducted to analyze the effects of three rainfall intensity (0.5,1.0,1.5 mm/min) on runoff and sediment yield in purple soil. The results showed as follows. Under 50% and 75% vegetation coverage, (1) The greater the rainfall indestiny, the more the runoff production rate and the runoff volume in the purple soil. In the same time, under the three kinds of rainfall intensity, the surface runoff accounted for 18%, 30%, and 52% of the total runoff volume, respectively. (2)The greater the rainfall intensity, the more the sediment yield and erosion rate occured. In the same time, under three kinds of rainfall intensity the sediment yield in purple soil accounted for 13%,33%, and 54% of the total sediment yield, respectively. (3) The particle size of water-stable aggregate in erosion sediment was mainly concentrated in < 0.25 and > 3 mm. The total amount of the two particle size accounted for 74% and 67% of the total sediment, respectively, while water-stable aggregate particle size of 0.25~3 mm accounted for 30% and 26%, respectively. (4) There was a significant positive correlation between rainfall intensity and the yield of runoff and sediment in the purple soil (P < 0.01). The linear equation was synthesized by rainfall intensity and sediment yield. The correlation coefficients were 0.96 and 0.97, respectively. A linear equation and a quadratic equation were synthesized by rainfall intensity and runoff yield, respectivelly, and the correlation coefficients were 0.89 and 0.94, respectively. The results can provide references for controlling soil erosion in purple soil and revealing related erosion mechanism.