Abstract: Soil erosion and geomorphological characteristics of its spatial distribution in the Maquan River basin, which was taken as a case for study of the Yarlung Zangbo River source area, were studied, with remote sensing and GIS technologies. Results show that the area under soil erosion above light is 18 933.33 km2 , accounting for 71.86% of the total source area; freeze-thaw erosion is the major form of soil erosion, accounting for 82.53%; wind erosion occurs only in wide sections of the river valley, accounting for 5.33%; and water erosion, often mild in intensity, is small in area. Geographical distribution of the soil erosion is highly influenced by altitude with significant vertical differentiation. Soil erosion is mainly distributed in areas relatively low in slope or flat in topography. Extremely strongwind erosion occursmainly on slopes facing southwest, and quite little on slopes facing south, west and south-east and in flatland, while strongwind erosion mostly in flatland, and some on slopes facing northeast and west. Aspect of a slope does not affect much on freezethaw erosion.

Key words: freeze-thaw erosion, wind erosion, alpine-desertified and, source area of the Yarlung Zangbo, soil erosion