关键词: 塔克拉玛干沙漠, 第四纪沉积物, 机械组成特征, 风成砂

Abstract: Taklimakan Desert covers the wide centeral area of the Tarim Basin. The characteristics of the mechanical composition of the Quaternary deposits in the desert region show that the desert has developed at a wide flood-plain. As the rivers（specialy coming from the south）acted in the centeral desert region in a large range until early Holocene, fragments of rocks and minerals, which were acted on by wind and flowwater, were in a long term！ ciculation of changing from alluvial deposits to colian deposits, and again to alluvial, to colian. The wind or the flow-water constantly brought new materials from the uper wind direction or the uper streams into the circulation the grian size composition of the sand dunes at the peri-desert region also told us that the movement of the sand dunes and the flow of the shifting sand not only promote the vicility desertified land but also directly enlarge the desert range, and hazard human activities.