Dianchi watershed is located in Kunming basin, Yunnan Province. Karst rocky desert is comparatively developed, with 225.56km2 of rocky desert that accounting for about 7.71% of the total area and 32.69% of the karst area in Dianchi watershed. The deserts mainly locate in Wanghaishan, Dabanqiao-Chenggong, Heilinpu, Haikou, Liangwangshan and Shangsuan etc. Among them, the most serious desertification area is the district in the northeast of Dabanqiao. The desertification has led to detriment as serious soil loss, arable land decrease and soil moisture retention capacity reducing as well as environmental degradation. Through field survey and ETM interpretation, it is found that the desertification is intimately related with natural factors as lithology, karstification, geomorphology and climate, and with human factor, as well as with industrial pollution. To against the genesis of the desertification, the governing measures are put forth, such as ecological restoration, farmland capital construction, water resource exploitation, rural power source construction and small town build as well as reasonable use of land.