Abstract:Kumtag desert, China's sixth largest desert, lies in the south-east of the Lop Nur region,and is famous with the unique dune type of Pseudo-feathery dunes in the whole world. Kumtag desert is expanding and threatening to engulf previously productive lands with its arid wasteland character with the speed of 1-4 m eastward annually. Tamarix sand-hillocks is a frequent special biological landform types, with legible age layers structure composited by sand and plant litters, in Kumtag desert. And it is very important for regional environmental evolution research because of noting the desert environmental information diversification. In the present paper, we try to explore desert environmental change process of Kumtag desert based on stable isotope techniques collecting stable carbon isotope sample of Tamarix sand-hillocks from the different habitats and set up the stable carbon isotope series in age layers of four typical Tamarix sand-hillocks, proluvial landforms, wedland landforms,YaDan landforms and valley landforms, meanwhile environmental information and local meteorological data were collected as well. The results showed that the ratio of stable carbon isotope (δ13C), in age layers of Tamarix sand-hillocks, was fluctuated during 40-60 s of twenty century, and had declined since 1980s. The change tendency of stable carbon isotope series was accord with the stable carbon isotope downtrend of tree-ring all over the world. It was indicated that atmospheric CO2 concentration increasing affected the carbon isotope of stable carbon isotope (δ13C) in age layers of Tamarix sand-hillock. The resolution ratio(Δ)of stable carbon isotope in age layers of Tamarix sand-hillocks had a similar change trendency to the global climate changes. It was dry and warm climate environment in the recent 120 years, which the resolution ratio(Δ)was reduced with the global climate warming. However, the climate environment was colder and moister before the industrial revolution in the nineteenth century, and the resolution ratio(Δ)was rosen. There was different response of the solution ratio Δ of stable carbon isotope in age layers of Tamarix sand-hillocks under different habitats to climatic elements changes. In the high altitude area, the resolution ratio(Δ)in age layers was restricted by several climatic factors. e.g. air temperature, humidity, atmospheric pressure, etc. the resolution ratio(Δ) composition had significantly relationship with annual air relative humidity, annual precipitation, seasonal atmospheric pressure and seasonal illumination intensity. The resolution ratio(Δ)composition was affected by several climatic factors, but the hysteresis effect was not obvious. On the contrary, in the arid desert area in low elevation, the resolution ratio(Δ) composition had had greatly sensitivities to annual temperature, seasonal precipitation and seasonal air relative humidity, and the hysteresis effect was obvious.