This paper attempts to apply Geographic Information System(GIS)technology,and utilizes the Universal Soil Loss Equation(USLE)to estimate the potential soil losses and the actual soil losses in Hainan Island.Some important data such as the spatial distribution characteristics of soil conservation of ecosysstems in Hainan Island have been got.The results shows the soil conservation capacities of the mid mountain area ecosystems are the strongest in Hainan Island.The market valuation,opportunity cost and sh...