Land degradation caused by water erosion in South China took place mainly due to the vulnerabilities of its ecological environment,such as thin layer of top soil,poor nutrition and moisture and low erodibility of subsoil as well as a marked summer drought.Depletion of vegetation cover induced by adverse human activities provides a breakthrough point for its initiation,and abundant rainfall and frequent rainstorms and typhoons in summer act as the exogenous agent for its development.Land degradation in South China manifests itself as not only soil degradation but also vegetation degradation and deterioration of land surface.Its development could be considered as a multiple vicious circle of the process:vegetation degradation soil degradation deterioration of land surface.Tentative criteria for land degradation assessment were set up,including vegetation types and cover,types and percentage of surface materials exposed as well as erosional morphology and its percentage.