Abstract: Loess Plateau of northern Shaanxi Province is an important soil erosion area and Grain for Green Policy (GGP) implementation area in China. After 10 years implementation of the policy, the regional ecological environment has been improved obviously. Scientific evaluation of GGP’ s influence on soil erosion is helpful to the adjustment and improvement of this policy. The author took Yan’an area as an example, evaluated GGP’ s influence on soil erosion based on land use data, MODIS NDVI, DEM and precipitation data. The results showed that: (1) influenced by the implementation of GGP from 2000 to 2010, farmland in the area of Yan’ an and ＞25° farmland significantly decreased, mainly converted to grassland and woodland and the conversion ratios were over 80% and 15%, respectively; (2) ＞25° farmland in the area decreased 207.8 km2, reduced by 47.50%, but only accounted for 8.8% of total returning farmland area in Yan’ an; ＞25° farmland should be all returned due to its important role in soil erosion; (3) the implementation of GGP increased average NDVI value, the NDVI value of Yan’ an area and ＞25° area increased by 53.76% and 55.29% from 2000 to 2010, respectively; (4) the reduced area of farmland in 2000 to 2010 did not offset the soil erosion caused by the increase of rainfall erosivity. GGP really played an important role in reducing soil erosion calculated by rainfall erosivity in 2000. Since soil erosion reduction is a long process, the author suggested maintaining the GGP achievement, and continuing the improvement and recovery of vegetation.