Eco-hydrological processes in the earth surface system reveal the ecological pattern of hydrological and ecological processes change mechanism, and reflect the development and evolution processes of the earth surface system. The ecological hydrological processes were simulated in the study using SWAT (Soil and Water Assessment Tool) model, which is developed by the United States Department of Agriculture (USDA) Agricultural Research Service (ARS). First, the space and attribute databases model required were constructed. Secondly, based on digital elevation model (DEM) the hydrological parameters were calculated, including determine the grid cell flow, calculate the unit catchment area, divided watershed boundaries, generate river nets, divide sub-basin. Based on the parameter sensitivity analysis, the eco-hydrological process simulation was completed through the model calibration and validation. Then the potential evapotranspiration, actual evapotranspiration, soil water, water yield and other eco-hydrological parameters were selected for analysis. The results show that trends of potential evapotranspiration and actual evapotranspiration in study region are consistent, and the values are almost the same. Monthly soil water is between 150mm and 200mm, and strict correspondence to precipitation. It is a certain correlation between soil water content and evapotranspiration. When soil water content is low, evapotranspiration is small, but there is about two months of the time lag. The characteristics of ecological and hydrological processes in study region show typical southeast coast in China.