Through conducting field investigations and using digital methods of remote sensing and geographical information system techniques,we analyzed the dynamic changes of sandy desertification land of the north of Otindag sandy land based on the TM images of 2000 and 2005.The data adopted in this study were composed of two types,namely,census data of 2000 and 2005 and remote sensing(data).The datum source of sandy land and the(data) in 2005 came from the interpretation of composite Landsat 5 images of bands 4,3 and 2(R,G,B) according to the local conditions and land use status of sandy desertification.In order to minimize possible interpretation errors,a set of interpretation indicators was established based on field investigations.The area measurements of these types were made using the statistics function of GIS.Results indicated that the development and reversion of sandy desertification co-exited in the study area,and the area of sandy desertification land increased by 1 366.057 from 2000 to 2005.In terms of the extent of sandy desertification,the area of the light sandy desertification increased 239.806 km²,the area of the moderate,1025.393 km²,and the area of the severe,850.396 km².However the very severe sandy desertification decreased 749.539 km².In terms of the administrative region,the areas of sandy desertification land in Sonid Youqi,Sonid Zuoqi,Abga Qi,Xilinhot,Hexigten Qi,Xiujimqin Qi were 1 038.377 km²,185.487 km²,15.715 km²,51.554 km²,(5.492) km²,69.431 km²,respectively and area of sandy desertification land in Linxi had not clearly changed.In general,the status of sandy desertification in the North Otindag sandy land is still serious.