The wind-born sandy region along the Great Wall in northern Shaanxi Province of China is located in the southeast edge of the Maowusu desert. The ecosystem is highly vulnerable and it is active in moving southeastward over Maowusu. Interannual variation of vegetation coverage and its relationship with climate in the region between 1981 and 2003 were examined by using the monthly GIMMS （Global Inventory Modeling and Mapping Studies）NDVI (Normalized Difference Vegetation Index) data and local meteorological records. Vegetation coverage of the region was generally improved in the past 23 years but with substantial variations. Area of lower vegetation coverage decreased in contrast to the increase of higher vegetation coverage area. Summer NDVI was the highest in a year followed by its autumn value. Increasing trends of NDVI were found in spring, summer and autumn. The vegetation conditions in summer or autumn determine the annual coverage. Correlation between NDVI in the two seasons was found to be highly correlated with its annual values. The NDVI increased slowly in spring and decreased rapidly in autumn. The annual mean NDVI showed positive correlation with precipitation, but not with temperature. There were significant positive correlations between winter precipitation and spring NDVI, spring precipitation and summer NDVI, and summer precipitation and autumn NDVI. The correlations between summer and autumn precipitations and annual NDVI were both significantly positive. The results indicate that rainfall is a key factor in determining the distribution of vegetation over the region. Annual precipitation did not increase significantly during the study period, but annual NDVI continuously increased. This implies that precipitation was the main driver for NDVI interannual variations and anthropogenic factors such as reforestation and grassland recovery were the cause for the increasing NDVI trend.