Investigation was carried out on the main plant communities in Yanchi sandy land by sampling method and soil water content was measured on each sample plot,as well as the seasonal change of soil water content in the different plant communities.Results show that plant communities on the flat sandy land with impermeable stratum below root layer,in terms of average soil water content in different plots,ranke in the ascendant order of Leymus secalinus community (4.91%),Oxytropis aciphylla community(7.42%),Caragana korshinskii Community(10.36%),Artemisia ordosica Community(12.55%),and bare sandy land(16.27%).In the same plant community,soil water content is different in different seasons.During vegetation construction on sandy land,we should select Caragana korshinskii and Artemisia ordosica as the main artificial vegetation species and control the density of plant in a reasonable range or distribute some proportion of bare sandy land to achieve a long-term stable state.