College of Geoexploration Science and Technology, Jilin University, Changchun 130026, China

Hulunbeier area is the major natural grassland and livestock base in China. The phenomenon of desertification in Hulunbeier increased along with the development of economy and society, and the irrational utilization of resources. Using artificial visual interpretation method combining with field survey to obtain 3 periods of interpreting data base on RS and GIS technologies, and applying MSS image data in 1970, ETM image data in 2000 and CBERS image data in 2007 as the data source, the authors analyse the spatial and temporal changes of desertification in Hulunbeier area. The results show that over the past 40 years the total area of desertification increased in this region, including in 1970, the area of desertification land was 7 408.76 km² , which to became 7 539.52 km² in 2000, and 7 852.12 km² in 2007, with total increasing 443.36 km² in area. During 1970 to 2000, the desertification decreased but salinization increased area was 134.09 km² , and the desertification increased but salinization decreased area was 53.35 km² ; while from 2000 to 2007, the desertification decreased and salinization increased 41.71 km² in area, and the desertification increased and salinization decreased 172.8 km².