An assessment model for sandy desertification in regional scale is established based on CBERS images in 2000 and 2006.Tendency of land cover change in Mu Us Desert is analyzed and desertification assessment in county scale is made.The conclusions are as follows:(1) Desertification in the study area tends to be steady.(2) The three types of semi-fixed desertification,semi-flow desertification,and non desertification change severely.(3) Result from desertification assessment in county scale shows that the number of extremely severe desertification counties decreases significantly and the counties turn to severe and moderate sandy desertification.Mu Us Desert is in a good status in general.