沙丘的粒度组成主要由风况、沙源、沙丘形态与气流之间的相互作用等决定，粒度组成可以反映沙丘的形成过程。对毛乌素沙地20个新月形沙丘及沙丘链，25个抛物线形沙丘的迎风坡脚、丘顶、背风坡脚表层0~5 cm进行了采样，并对其粒度组成进行了分析测试，来探讨其粒度特征。结果表明：（1）相比新月形沙丘，抛物线形沙丘分选性更差，悬移组分更高；抛物线形沙丘迎风坡相比新月形沙丘分选性更差，粗沙含量更高。（2）沙丘的粒度分布模式统计中，新月形沙丘出现最多的是迎风坡最细的类型，占比65%，而抛物线形沙丘则倾向于背风坡最细类型，占比56%。（3）植被、新月形沙丘和抛物线形沙丘相反的形态以及形态与气流的相互作用是导致两种沙丘粒度差异的主要因素。

The grain size composition of dunes is mainly determined by wind regimes， sand sources， and the interaction between dune morphology and airflows. The grain-size composition of sand dunes can reflect the formation process of different types of dunes. Samples were collected from 0-5 cm of the surface layers at the foot of the windward slopes， the dune crests， and the foot of the leeward slopes of 20 barchan or dune chains and 25 parabola dunes in the Mu Us Desert. The grain-size composition of the samples was tested and analyzed to explore their grain size characteristics. The results show that： （1） There are no significant differences in grain-size composition and parameters between barchan dunes and parabola dunes， and the grain -size frequency distribution curves are typical single-peak shapes， but compared with barchan dunes， the parabolic dunes have worse sorting and higher suspended components； The windward slope of parabola dunes has worse sorting and higher coarse sand content than barchan dune. （2） In the statistics of grain-size distribution patterns of sand dunes， the barchan dunes tend to have the finest grain-size on the windward slope， accounting for 65%， whereas the parabolic dunes tend to have the finest grain-size on the leeward slope， accounting for 56%；The grain-size frequency distribution curve also indicated the biased results of the grain-size distribution patterns. （3） Vegetation， the opposite morphology of barchan dunes and parabola dunes and their interaction with airflows are the main factors that cause the differences in grain-size characteristics between the two types of dunes.