Abstract: The paper aims to analyze the influence of the strategy of returning the grain plots to forestry and grass since 2000 to Longnan City of Gansu Province，a high coverage area.Based on the MODIS EVI data during the period from 2000 to 2010, the spatial and temporal variation of vegetation coverage in the Mountain Area of Longnan was studied by using the EVI average analysis, method of vegetation coverage and linear regression trend analysis. The results showed that: The change of vegetation cover the Mountain Area of Longnan increased slowly with the increase of 0.2%/10 From 2000 to 2010, which was lower than that of He-dong region of Gansu Province, Gansu Province, Qinba mountain area and northwest China. Influenced by the distribution of regional elements such as temperature and precipitation, there was a obvious regional difference in vegetation coverage, which had a trend of decreasing from southeast to northwest. The vegetation types in the whole mountain area with vegetation coverage above 45% accounts for the majority part, which were the type of middle and high coverage, and high coverage vegetation., the proportion of forest land is larger than others in Gansu Province. [Conclusion]Although the area of vegetation improvement is larger than that of the degraded area, However, there was a trend of degradation in high vegetation coverage area, Considering the relatively fragile ecological environment, its not be ignored for the Mountain Area of Longnan to strengthen vegetation protection in the future ecological construction.