[Objective] In order to study plant adaptation mechanism under different landforms in drought regions.[Method] Observe soil moisture dynamic of Salix psammophila sample areas on the dune and depression with neutron moisture gauge and research the roots distribution of Salix psammophila sample areas on the dune and depression respectively by digging method.[Result] The quantity of Salix psammophila roots on the dune exponentially decreases while that on the depression decreases by power function in horizontal direction.In vertical direction,Salix psammophila roots on the dune are mainly distributed in 0-30 and 80-120 cm layers as 72% of all,while Salix psammophila roots on the depression are mainly distributed in 0-40 cm layers as 54% of all.[Conclusion] Salix psammophila roots on the dune not only use surface soil water but also use middle-layer groundwater.Salix psammophila roots on the depression primarily use surface soil water.
