The paper has investigeted the physio-ecologicl water relationship of the SPACsystem and water parameters of P-V curver of Caragana korshiskii growing in aeolian sandysoil. When the relationship between water content(W) and water potential(ψs) in the aeoliansandy soil is: ψs=- 40. 32196 ×0.42795w, W= 4. 5 %, is just the poit that convert the slowlyfall into the fast one. When W>4. 5 % , C. korshinskii grows very well. And when W is bellowto 4. 5%, the growth has been affected by W. The leave water potential...