Vegetation construction was an important approach to control soil erosion, especially in the slope soil erosion. Converting cropland to forest and grassland was a largest vegetation construction project in loess Plateau and even the whole country. In this study, the effects of revegetation on soil erosion under implementation of the Grain for Green Project were evaluated for five single years (1984, 1996, 2006, 2012 and 2014) using the revised universal soil loss equation (RUSLE) supported by ARCGIS 10.2. Daily rainfall data of three decades (from 1984 to 2014, excluding 1999) of Yan’an weather station was used to calculate the rainfall erodibility (R). Values of topographical factor (LS) were extracted from digital elevation model, which was generated by applying interpolation based on topographic map with a scale of 1∶5 000. The K factor was obtained using physical and chemical properties of soil samples of study area. C and P factors were generally derived from previous studies on the Loess Plateau. Results showed that areas of moderate high, high and very high erosion declined sharply, and most of them transferred to very low, low and moderate. The average soil erosion rate decreased from 15 327.57 t/(km2?a) in 1984 to 3 270.19 t/(km2?a) in 2014. Slope belts of 15°～25°, 25°～35° and ＞35° were the main areas of severe soil erosion. These three slope belts accounted for 44.93%，42.65%，35.78%，23.23% and 22.98% of total study area from 1984 to 2014. Furthermore, the areas with very low, low and moderate erosion occupied 26.53%, 44.24% and 43.47% of the total area of the watershed in 2006, 2012 and 2014, respectively. Generally, the soil erosion in Yangjuangou watershed reduced significantly. It was indicated that revegetation had positive effects on soil and water conservation and soil erosion, and the Grain for Green Project led to a success in soil erosion control.