The experimental data of sediment runoff in 3 years were analyzed in this paper. The results showed that: 1) The sediment runoff in slope wasteland was smaller than in slope cropland. 2) In cropland where the coverage was less than 30%, its silt runoff was greater than in wasteland. 3) If the gradient was greater than 25, the yield would decrease significantly after 3years cultivation though better output might get at start, and caused seriously soil erosion. So the perennial heeded to be planted. The results from the experiment also showed that the sediment mainly came from sloping field in granite area, the comprehensive control in slope cropland was the main way in increasing per unit yield and soil and water conservation.