Rocky desertification in the karst area is a land degradation process in nature where the rate of soil for 2mation is lower than that of soil erosion. Slope degree affects the extent of soil erosion. The greater slope degree is ,the more instable surface material is. The two maps of slope gradient and desertification distribution on a scale of 1 ∶ 500 000 in Guizhou Province were overlapped and analyzed in order to discuss the correlation between slope degree and rocky desertification. It was found that slop degrees ranged mainly from 10 ° to 25 ° . Where slope degree was greater than 25 ° , the possibilitiesof the desertification occurrence at low , moderate or strong rate were all very high. In addition , the occurrence of rocky desertification increased as slope increased , especially where slope degree was greater than 18 ° , the trend toward strong rocky desertification was apparent. The desertification was mainly at low or moderate extent where slope degree was less than 18 ° . The reasons for the correlation between desertification and slope degree in this region were discussed preliminarily.