Analysis of dynamic change in desertification is the foundation of desertification prevention.Multi-temporal TM image data of Kubuqi Desert in recent years were analyzed and different periods of desertification grade distribution maps were obtained by image interpretation using RS GIS software.Dynamic desertification process was discussed in terms of desertification area change and spatial changes of desertification levels.Results show an obvious downward trend of total desertification area after 1989.In view of the spatial variations of desertification levels,desertification is reversed in most areas along the main course of Yellow River,but increased in southeastern part,southern desert hinterland,and the surrounding of lakes.In addition to general engineering and biological measures,irrational human activities should be eliminated in order to maintain the dynamic balance of ecological systems and human environment.