Abstract: The Yarlung Zangbo River basin is one special zone in the south of Xizang, its types and distribution and causes of desertified land have special features. By use of the last data of desertification survey, this paper analyses the area, types, distribution and damages of desertification in Yarlung the Zangbo River basin. Through analysis on the factors influencing desertification and their relations, this paper makes use of some quantitative analysis method to study systematically the cause of desertification, and thoroughly studies the effective ways and its mechanism of artificial factors on desertification process in this special zone in the southern Xizang. The basic conclusions are as follows: There are 3 degrees and 5 types of desertified land in the Yarlung Zangbo River basin. The area of desertified land is 314.1?10⁴hm². The desertified land distributes in all over the basin. The development of desertification has caused serious damage in all over the basin and huge economic loss. Desertification in the Yarlung Zangbo River basin is one comprehensive process relating with natural factors and human ones, in which it is the physical factors that play a leading role. The climatic change and human activities have almost equal influence and effect on the development of desertification. It is claimed that the cause of desertification has regional feature. The effective ways of artificial factors on desertification in this region is different from that in the northern China. Artificial factors are not the leading factors yet, their influence is much lower than that in the northern China. The leading way which effects desertification in this region is over grazing, not over reclamation in the northern China. In the Yarlung Zangbo River basin, the influence of over reclamation is only a little.