Abstract:Biological soil crusts (BSC) are a universal and common feature in arid-semiarid habitats and polar regions. They contribute to the biodiversity of these ecosystems, and play significant roles in soil stability,ecosystem stability maintenance, nitrogen fixation, biomass production, and soil fertility. It was described that succession development of BSC′s different successional age and distribution of BSC in different areas. Responses of BSC to elevated UV-B radiation, climate warming and rainfall variation were separately introduced. It is prospected that making progress in research of BSC responses to climate changing, especially arid and semi-arid regions, at regional scale.