Land desertification investigation of the agriculture and graziery mixed area in Duolun region of Inner Mongolia was carried out twice within five years by means of TM image monitoring. The classification system of land desertification combining land desertification with land use can effectively delaminate and separate various sorts of land desertification by adopting a set of ratio combinations according to the vegetation indices. The first survey revealed that land desertification became increasingly serious due to excessive cultivation and grazing in Duolun County, and the second survey shows that the land desertification management has been effective and the trend of deterioration has been restrained. Remote sensing monitoring has been playing an active part in preventing and controlling desertification of that area.