Based on the experiment with two comparative methods,the water controlable pot planting and the PEG penetration stressing(0%,5%,10%,15%,20%),the water holding capacity of the leaf,relative water content,relative water deficit,relative electrical conductance,chlorophyll,MDA content as well as the photosynthetic physiological index were measured and the physiological property in drought resistance of Atriplex canescens was studied.The experiment results show that under water controllable pot planting for 6 days,the soil moisture decreased to 8.3% and did not affect the photosynthetic physioogical index very much.Under the water penetration stress conditions,the relative water content of the leaf,chlorophyll and the free water content of A.canescens seedling decreased while the relative water deficit,relative electrical conductance,MDA content and bound water content increased.Under the condition of serious water penetration stressing (15%,20% PEG),the above-mentioned physiological indices changed to a reatively large extent.The water holding capacity of the leaf of A.canescens is strong and its bound water content is higher and its drought resistance is strong.