Effects of soil surface characteristics and gradient on runoff and sediment production were analyzed by comparable experiments. It showed that soil crust and gradient both have effects on runoff by reducing infiltration; the contribution of soil crust is decreasing with gradient, whereas the contribution of gradient is increasing with gradient. On each gradient, the effects of soil crust are decreasing with rainfall time. Once soil crust formed, the increment of erosive force is larger than that of anti-erosive force, and so induces the improvement of sediment yield. It is still high of runoff and sediment yield for broken crust soil, and so it is impossible to eliminate the effects of soil crust completely only disturbing the soil surface.