Guizhou is a province of Karst development,it is affected by mankind action especially,and it isn' t unreasonable to using of land resource,flood disaster take place frequently. It lead to a series of environment problem. So people in karst region,if land desertification isserious,they are very poor. It enhances request of soil erosion work and building of ecological environment in karst region. The grade of land desertification is investigated and its space changeable,affecting parameters,causes and degree are analysed by GIS and remote sensing techniqu in Guizhou province,the map of land desertification in Guizhou karst region are made. Meantime,it is a completing way of science and technology,it is going to provide dependable data for soil erosion preventing and ecological environment managing.