Four periods' remote sensing images of Huoshan County were used to retrieval and calculate the NDVI of study region based on the RS and GIS technologies. The vegetation coverage of Huoshan was drawn by dimidiate pixel model. The vegetation coverage of four periods images were analyzed using the method of overlay assisted by the spatial analysis. Then the spatial-time changes characters of vegetation coverage were obtained, the practical data was used to evaluate. The high correlation of them was showed, and the precision reached 0.83. The vegetation coverage of the Huoshan has been greatly raised and the ecological environment of Huoshan is facing the right direction were showed by dynamic change.