Abstrcat Soil and water loss from sloping fields was the main reason for soil and land productivity degradation in mountain areas. Based on the experiments of rainfall simulation, this article assessed systematically the effect of tillage on water transformation and runoff-sediment-yielding characters on granite sloping fields. Results showed that under tillage conditions, the rate of water transformation increased by 1/4, the average sediment concentration in lost runoff increased by one and a half times, sedment-yielding amount increased by 12%. So various farming measures should be combinated organically. In addition, with the extension of runoff-yielding time during the rainfall process, the sediment from slope tended to accelerate more rapidly than runoff volume increase. So the applications of suitable measures to prolong the initial runoff-yielding time, reduce runoff-yielding volume, and increase the transformation ratio from rainfall to soil water will be effective in reducing soil loss from sloping fields in these areas