A study on the physicochemical property of four karst mountains desertification soils in Xichong county of southeastern Yunnan was conducted by ocean weather station observation. The results showed that the land capacity of rendzina is the highest and the land capacity of terra rossa is higher, which resulted by closing hillsides to facilitate afforestation for many years of rendzina,and balance fertilizing of terra rossa. As returning land for farming to forestry,the physicochemical property and land capacity of brown rendzina has been greatly improved after three years. Closing hillsides to facilitate afforestation, returning land for farming to forestry and balance fertilizing are three good land capacity improvement approaches in karst mountains desertification soil of southeastern Yunnan.