This article uses the localization to take a sample and to dry the law,has determined the Yulin sand district several trees soil moisture.The results are as follows: soil moisture content's vertical distribution pattern is lowest for the surface layer soil moisture content,along with depth of soil increase,the soil moisture content assumes increases the tendency;Soil moisture content's season dynamic rule has the obvious seasonal variation rule for the different tree species soil moisture content,the soil moisture content may divide into three stages according to the seasonal variation,soil moisture weak dehydration stage from April to May,soil moisture consumption stage from June to August,soil moisture restores the stage slowly from September to October;Various trees' soil moisture change rule for Pinus sylvestris var.mongolica>Caragana korshinskii>Amorpha fruticosa>Salix psammophila>Artemisa arenaria DC.>Hedysarum scoparium-Hedysarum fruticosum.