Abstract: To illuminate the physical mechanism for the formation of soil surface crust and present the theoretical foundation for preventing the formation of crust, three types of arable soils in China, for example, loess, red and black soils, were used to investigate the effects of wetting rate on surface strength and aggregate stability without rainfall, under wetting rates of 2 (slow), 10 (middle) and 50 mm/h (fast). The results indicate that the effects of wetting rates on surface strength are decreased in the order of loess> black soil> red soil. The aggregate stabilities have the order of red soil> black soil> loess. Except slow and middle wetting rate for loess and red soil, there are significant differences of mean weight diameter (MWD) among different wetting rates with different soils.