Using simulated rainfall test method, in which slopes were 3°, 5°, 7°, 9°, 12° and 15° and rainfall in-tensities were 70, 100, 120 mm/h, regulations of the runoff and sediment varied with the rainfall intensity and slopegradients were studied. The results showed that under weak rainfall intensity, runoff time was long and effect ofslope gradients on runoff time was less. Under bigger rain intensity, runoff time was short and effect of slope gradi-ents on runoff time was significant. On slight slope, effect of rainfall intensity on runoff erosion was less; on steepslope, effect of rainfall intensity on runoff erosion was bigger. Under the same rainfall intensity, rate of sediment in-creased when the slope increased, and this relationship was affected by the rainfall intensity. There was the criticalslope between 12ånd 15°. The rate of runoff erosion and the amount of sediment reduced quickly when the slopewas over 12°.