Land degradation, an important sustainable development issue, is defined as this: the diminution or destruc tion of the biological or economic potential caused by one or a combination of processes actiong on the land. The processes include water erosion, wind erosion, and longterm reduction in the amount of natural regetation. There is severe water erosion in the granite weathering crust area in southern China. As a result of water ero sion，desertlike landscape appears in the place such as badlands, deterioration of soil properties and vegetation degradation. For example, 2700 of total area in Wuhua county, Guangdong Province, has suffered from badlands. In consideration of the badlands that are mainly landscape in the process of degradation，in which vegetation cover age, density of gully and weathering layer condition as well as erosion type can be regards as the indicator to assess land degradation. Finally, this paper discusses the negative effects of land degradation on social and environment.They include destruction of land resource, silation of reservoirs and reducement of plant growth etc.