Vegetation is a natural bridge that links soil, air, water and other elements of the nature, and also an important direct factor of ecological environment. Because satellite remote sensing has advantages of simultaneous and time-intensive observations, data comparability, etc. , it provides a powerful tool for dynamic detection of vege-tation in large areas. In a variety of surface parameters, NDVI (normalized difference vegetation index)is especial-ly sensitive to vegetation growth and can represent the change of vegetation coverage to some extent, so NDVI is re-garded as the best instructing factor of surface vegetation. There have been a lot of studies using NDVI, but most of the previous studies focused on the relationships between climatic factors and vegetation indices or explored the dy-namic change of vegetation in some specific regions by analyzing the dynamic change of NDVI. It is believed that the multi-year average of vegetation index reflects a normal state of vegetation coverage, so another important appli-cation of NDVI is to use the average value to study the spatial distribution of regional vegetation and its affecting fac-tors. The Qaidam Basin is characterized by the diverse terrains, significant vertical differentiation and quite inho-mogeneous spatial distribution of vegetation. Because of its special geographical location and climatic characteris-tics, its ecological environment is relatively vulnerable. Therefore, the study on the spatial distribution of vegetation coverage and its affecting factors in the Qaidam Basin using data series of NDVI is of great significance both for the expansion of NDVI application and the ecological conservation in the Qaidam Basin. In this paper, the spatial dis-tribution of vegetation coverage in the Qaidam Basin is analyzed using GIMMS (global inventory modeling and map-ping studies)/ NDVI data set from January 1982 to December 2006. The factors affecting the spatial distribution of vegetation coverage in the Qaidam Basin are also analyzed based on the data of precipitation, terrain, stream sys-tems, land use and the map of vegetation distribution in the basin. The results showed that the vegetation coverage is generally low in the Qaidam Basin, where the long-time average annual maximum value of NDVI ranges from 0.032 6 to 0.583 7 and only 0.140 4 in average. There is a clear semi-ring structure of vegetation coverage from the southeast to the northwest. There are four main factors affecting the spatial distribution of vegetation coverage in the Qaidam Basin, i. e. , precipitation, hydrological conditions, altitude and human activities. Specifically, there is a good correlation between the average annual precipitation and the three-layer semi-ring structure of vegetation coverage. The effect of altitude on the distribution of vegetation is relatively complex. The effects of hydrological conditions and human activities on the distribution of vegetation are mainly embodied in local areas.