Abstract: Soil microbiotic crust is developed broadly and has an ecological significance in arid and semiarid regions. This paper reviewed the advances of domestic and overseas studies, which on characteristics of the formation and development of microbiotic crust, its effects on microhabitat, including physical and chemical properties of soil, endurance to wind and water erosion, the distribution of precipitation in spatial and time, nutrient and chemical elements variance in soil process and geo-bio-chemical cycling process, and influence on vegetation dynamics. In addition, the several contradictory research conclusions were synthetical analyzed. The role and function of microbiotic crust in ecological restoration of arid and semiarid regions of China were discussed.

Key words: arid and semiarid regions, soil microbiotic crust, ecological process, soil process