Abstract: By analyzing grain-size characteristics of surface sediments as related to wind force and vegetation cover in the eastern sand area of China, this paper discussed the modern aeolian sedimentary environment and the regional differences. The results show that with a unimodal distribution pattern the grain-size of the surface sediments of each desert and sandy land in the eastern desert regions is similar. All of the surface sediments are mainly composed of fine sand and medium sand and moderately sorted. Both grain-size composition and sorting differ from those of the western deserts. Controlled by the properties of the aeolian environment and the intensity of aeolian activities that were determined mainly by wind force and vegetation cover, grain-size characteristics of the surface sediments exhibit regional difference in the eastern desert regions. Specifically, grain-size in the Hobq Desert implies a typical desert environment that is characterized by frequent alternating processes of wind erosion, particle transportation and deposition; In the Hulunbeir Sandy Land, it is characterized by a wind erosion dominated aeolian environment; In the Otindag Sandy Land, Horqin Sandy Land and Mu Us Sandy Land, grain-size and aeolian activities are relatively complex, which is related to the mosaic distribution pattern of wind erosion dominated areas and aeolian deposition dominated areas. Statistics shows that both the mean grain-size and the sorting of the surface sediments significantly correlated to the annual average wind speed and the total vegetation coverage in the eastern desert regions.

Key words: eastern desert regions, grian-size, aeolian environment, regional difference