The temporal and spacialvariety of
soil water content of shifting sand and four main plant community on
Otindag sandy land
was measured by orientationsampling and drying means.The results are as follows:the soil water contentprofiles of shiftingsand nune and plant community devided into three layers from top to bottom: water active layer,subactive layer and relative stablelayer.The variety of water active layer had relations with root system distribution,the water active layer distributed deeply with deep root plant.The water temporal variety of sand were notable,The dry and humid change of soil moistureof whole season present "S"shape.Based on the seasonal variation of sandy soil moisture,it can be divided into three phase: the soil moisture stocking phase from April to May,the lose phase from June to September,the slowness refilling phase from Septemberto October.The water soil content variety is mainly affected by precipitation,vegetation and site factors,the temporal and special differentce of
soil water content attribute to the difference of soil mechanical compositionand surfacee vegetation coverage.