Abstract: Many environmental problems facing people are related with land use /land cover ch-anges nowadays.Taking two false color composite Landsat5TM(Thematic Mapper)images of band4,3and2taken in1995and2000as data sources,this paper carried out studies on land use and land cover changes of Hexi Corridor in the last5years by interpreting,on the basis of Geographical Information System(GIS)software,Chinese version of Arc info7.1,according to land resources classification system of1:100000Resources and Environmental Database of Chinese Academy of Sciences.The results show that great changes have taken place in land use and land cover in Hexi Corridor since1995:(1)The number of land use patches and the total length of patch edges tend to increase,which show that the landscape fragmentation was strengthened.(2)Changes of land use structure show that cropland,woodland and urban and built - up area increased evidently.On the contrary,water area and grassland tend to decrease.These changes reflect the deterioration of eco - environment and the acceleration of urbanization.(3)Regional differences of land use and land cover changes are evident ,which are characterized by the increase in cropland,woodland,water area and urban and built - up area and decrease in unused land and grassland in Jiuquan and Jiayuguan located to the west of Hexi Corridor;the increase in cropland,woodland and urban and built - up area and decrease in unused land,water area and grassland in the middle of Hexi Corridor,Zhangye City;and increase in cropland and urban and built - up area and decrease in grassland and water area in the eastern part of Hexi Corridor,Wuwei and Jinchang.

Key words: land use changes, land use structure, regional differences, Hexi Corridor