| Lop Nur Region and its adjacent areas are located on the eastern Tarim Basin. Its north is the Kuruktag Mountain, northeast is the Keziletag Mountain and the Yigtag Mountain, east is the Baishan and Gansu Province, south is the Aljin Mountain, and west is the Taklimakan Desert and the Kumtag Desert. Eastern Aqik Valley is linked with Shule River and Hexi Corridor. The topography is like an inverted bottle. Lop Nur is the destination of every river in Tarim Basin. Its environmental evolution is the epitome reflecting on the Tarim Basin and surrounding mountains .Winter climate in this region is dry and frigid, summer has little rain and high temperature. Tamarix Cone is a kind of biological landform. Some of them have the clear "annual stratum" structure and the function of dating and storing environmental information as tree rings. From the analysis on the spot and reconnaissance report, Tamarix Cone in the Lop Nur Lake region of southern Xinjiang are mainly distributed in the deltas of Tarim River, Kongque River, Milan River. etc.The Subject investigated of this paper is with Tamarix Cone in Lop Nur region, utilize geomorphology method, on the basis of inspecting and observing in open country, testing the analytical means combining with the deposit size experiment etc to research the characteristic of grain size and the cause of Vegetation Dunes in Lop Nur Drainage Area. The basic conclusions are as follow:①All of sandy materials of sedimentary veins in studied section mainly consist of the fine sand, clay is little. Sand materials average particle size is followed by 3.20Ф, 2.76Ф, 3.40 in which of three Tamarix Cones. Besides of the sedimentary thickness of sandy materials, the grain-size composition,parameter of grain-size characteristics, and very little gravel sand content, grain-size distributed curve as well as accumulated probability curve have more clear environmental indication.②By the comparative analysis of Tamarix Cone grain-size data in the different locations of Lop Nur Region, we do research into the change of wind strength and provenance during different periods to obtain the information of environmental change during the last one hundred years.③By means of comparative analysis of grain-size of the Tamarix Cone, desert sand dunes and coastal zone sand dunes, they also response the unique function in the area of geomorphologic processes of wind-drifting sand, environmental evolution and land-cover change in order that they can provide new theoretical basis and technical reference for the research of environmental change in relevant areas.④The sand bed thickness is related to the surface sand richness. For Tamarix Cone, the richer sand source around, the higher sand bed thickness every year. According to the relevant meteorological data, the climate in Lop Nur region has been changing from more drying to more humid over the past one hundred years.⑤The sand particle size of Tamarix Cones was a regular pattern change on different parts, the sand particle size of windward base of slope and middle slope is rough on the leeward side, sediment particle size of slope's tip is minimum. It can be believed the sand particle size of Tamarix Cone on different parts that have relation to the winds and the source of material, meanwhile the plant in dunes will increase the surface roughness of the sand to block airflow dissipation. So changes in the structure of air flow in Tamarix Cone is showing the corresponding particle size characteristics on different parts.
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