Soil and water loss is one of the most vital environmental issues in China.Since the 1930 s,soil scientists have been observing the role of soil crusting and sealing in the processes of soil erosion.They have found that the existence of soil crust always decreases the land in infiltration rate and roughness of the surface,thus increasing runoff rate and anti-splash ability of the soil.Some studies have demonstrated that erosion modulus and cumulated sediment yield increase several or even dozens of times as much on crusted soils because soil crust augments kinetic energy of runoff,resulting in rill erosion.Unfortunately,critical values and related factors that affect forming process of soil crust are still not well understood.In order to clarify processes and factors of soil crusting,several types of soils were studied through art ificial precipitation,micro-conformation observation and physical and chemical analysis,and extents of different factors affecting soil crusting were also analyzed by SPSS.Results indicated that soil texture is the main factor for crusting,and soil clay minerals composition may be another main factor.Surprisingly,they also demonstrate that indexes of soil configuration and soil colloid have no obvious relationships with crusting and sealing.