Based on the two field studies in Qaidam Basin Desert, sediments of linear dune and barchans dune that are distributed along the prevailing wind in Chaerhan Salt Lake were collected as samples. Then, the grain size of the selected samples was analyzed. The results showed that fine and medium sand was dominant in the sand, sandy clay and fine silt was also detected in a large quantity. The grain size changed from coarse to fine along the prevailing wind. Moreover, the grain size parameters implied that the mean diameter of the samples was higher than those collected from the other deserts in China, which indicated a higher maturity values of linear dune over those of barchans dune. Finally, the cumulative frequency curve demonstrated that the sandy area under research was primarily deposited by saltation and suspension population.