Abstract: This paper analyses the environment structure of earth surface and the changing characteristics of species diversity during the process of desertification in the sandy hill area of Poyang Lake,southern China.Based on the frequency of plant species occurrence at different types of desertificated lands and the life-form composition of plant species at different stages of desertification,the characteristics of plant species' colonization and extinction were discussed.The indices of species diversity showed that the process of desertification was a process of biodiversity losing.Especially,the desertification will result in the extinction of endemic species first,then the rare species.In terms of the plant life-form,perennial herbaceous and arbor plants were severely affected by the process of desertification,whereas shrub species survived at all stages of the process of desertification.During the process,the extinction rate of plants was higher than the colonization rate.To construct recuperative ecosystem of sandy hill,conducting ecology recombination required ecostorage in the sandy hill area and outside of it as well.Ecological preparation of this dual storage is also required considering the realistic conditions.