Land degradation is a great threat to the world for the future, and it is not merely an environmental issue, but has been a social and economic problem as well. The source region of the Yellow River located in the northeast of the Qinghai-Xizang Plateau, and its eco-environment is very fragile for the especial geographic location in recent years. The eco-environment degrades very quickly influenced by natural factor together with human being factor in these years, in which desertification is main aspect of environment changing in this region. However, the previous study on the desertification mainly focused on the Gonghe Basin, and the systematic research was unavailable. This study showed, for the first time, the present status, classification and spatial distribution of land desertification in the whole region, based on the data obtained through field investigation and Landsat TM image (4,3 and 2 bands) of September 2000. According to our research, the desertified land in the study area mainly concentrated in the Gonghe Basin and Upland Plain Area, and the total area of desertification land is 13434.8 km2 , or 14.65% of the entire land in the aim region.
