Abstract: An unsupervised approach based on the Applied Resource Image Exploitation System (ARIES) was applied to land type mapping in the southern fringes of the Mu Us Desert in China, using multispectral data from LA NDSAT Ⅰ and LANDSAT Ⅱ. Despite the lack of ground truth information, sand dunes were consistently discriminated from vegetation areas. The satellite data were compared to information derived from 1945 air-photos and published sand distribution maps of 1953. It was established that desert expansion occured in part of the study region during 1953-1978. Some local increases in vegetation cover were observed in southern Yulin.