Wetland ecosystem,called as the kidney of the earth,is the main part of terrestrial ecosystems. Wuliangsu Lake,as a large-scale,multi-function lake-wetland in the semi-desert area of China,has high ecological and social value. Vegetation cover is an important indicator used to monitor vegetation change for evaluating terrestrial environment. In this paper,remote sensing images from Landsat TM were used as data sources to study the change characteristics of Wuliangsu Lake in 3 periods (1987,2000 and 2010). The normalized difference vegetation index (NDVI) was calculated based on the TM satellite image data,and was in turn used to estimate vegetation cover at Wuliangsu Lake. The results showed that vegetation coves increased from south to north across Wuliangsu Lake during 1987 to 2010. The proportion of < 20% vegetation cover decreased from 30.81% to 16.57%.The proportion of 20% - 50% vegetation covers was not significantly changed with 14.50%. The proportion of high vegetation cover (> 50%) increased significantly,which raised from 15.68% to 31.05%. In the whole region,the area of desertification land was decreased,while the farmland area was increased gradually. Climate change and anthropogenic factors are two driving forces in the change of vegetation cover. Human factors not only include the impact of human activities on vegetation boimass,but also in terms of the impact of different types of land use and related policies;climatic factors are mainly temperature and precipitation.