Applying Geographic Information System (GIS) technology, and adopting Universal Soil Loss Equation (USLE), the potential soil losses and the reality soil losses in Hainan island was estimated, the soil erosion factors (R, K, LS) in Hainan island were analysed, the spatial distribution of soil erosion characteristics in Hainan island was presented. The result shows the potential and reality soil erosion in Hainan mid-mountain area is serious.