Desertification,as a prominent environmental problem in southwest karst rocky region,is a problem particularly for the regional economic development and ecological construction,challenging the comprehensively sustainable development in this region.According to domestic and foreign literature,a desertification model was developed based on analysis of the concept and characteristics of desertification.The feedback mechanisms between desertification and background environment were discussed.The model divided risk pressure into four categories,i.e.,disturbance,accumulation,succession,and fragmentation.The risk factors of desertification were then analyzed and classified based on the pressure—state—response model.An assessment system for desertification risk was establishment for karst rocky areas.