Abstract: Abstract: Land desertification is a major global ecological problem that affects sustainable development of human society. Flow sand dunes are the main source of aeolian sand-dust transport in the surface layer, which causes enormous losses in many arid and semi-arid regions of the world. Aeolian dust transport processes are closely related to the variation of the surface vegetation cover. Therefore, it is necessary to screen plants with strong sand fixability to control the expansion of desert. The Ulan Buh Desert is one of the fastest developing areas of desertification in China. In this study, we aimed to investigate the changes of environmental sensitive particle components and factors affecting vegetation coverage, which would help to describe the process of surface sand movement accurately, and to compare abilities of different plant species to stabilize sand and provide reference for vegetation restoration in the area. The surface (0-2 cm) sediment particle size of five kinds of desert shrub dunes in desert-oasis ecotone at the northeast rim of the Ulan Buh Desert was measured by the laser diffraction method. The eolian environment sensitive grain size components were extracted by grain size class-standard deviation method. Then the sand stability capacity of plants was evaluated according to the changes of sensitive components. And the response of sensitive components to the changes of plant morphological indexes was fitted by multiple linear regression method. The results indicated that the frequency distribution curves of surface sediment under Psammochloa villosa, Agriophyllum squarrosum, Phragmites australis coverage and flow sand dune were single peak type, while under Artemisia blepharolepis and Nitraria tangutorum coverage, they were double-peak type. When the surface was covered by vegetation, the content of fine sand and middle sand reduced, while very fine sand and silt increased, the sorting became worse, the skewness deviated from normal distribution and turned to partially positive, and the kurtosis were decreased. The vegetation under which particle composition ranged from fine to coarse was as follows: Nitraria tangutorum> Artemisia blepharolepis > Phragmites australis > Agriophyllum squarrosum > Psammochloa villosa > flow sand dune. There were two sensitive grain size components of 1.45-76 and 76-456 μm in Ulan Buh Desert, named as fine sensitive components and coarse sensitive components, while the median diameter of two kinds of environment-sensitive particle size components were 57.3 and 193.6 μm, respectively. The fine sensitive components correspond to the suspended load in the sand drift activity, while the coarse sensitive components correspond to the saltation load. The contents of sensitive components were significantly (P<0.05) different under the coverage of each desert shrub. The content of fine components of different shrub dunes were as follows: Nitraria tangutorum> Artemisia blepharolepis > Agriophyllum squarrosum >Phragmites australis > Psammochloa villosa > flow sand dune. At the same time, the content of coarse grain size components showed the opposite law, which meant the ability of five kinds of desert plants to weaken wind erosion was correspondingly reduced. Multiple linear regression analysis showed that the content of fine components was positively correlated with plant height, crown width and branch number, and negatively correlated with porosity of what?(sand dune or plant cover?). With the increasing of the content of fine components in surface sediments, the cause also became complicated.