Abstract: The physiological indexes of leaves of Pugionium cornutum （L.） Gaertn. seedlings under artificial simulation drought stress conditions were determined by using leaves of annual Pugionium cornutum （L.） Gaertn.seedlings. The results showed that under mild drought stress conditions,the relative water content of sand was 4.4 percent point less than that of control;under moderate drought stress conditions,the relative water content of sand was 27.45 percent point less than that of control and the reduction was obvious;under severe drought stress conditions,the relative water content of sand was only 18.23%.The nature saturation deficit of Pugionium cornutum （L.） Gaertn.seedlings was gradually increased and was significantly higher than that of control （P〈0.01）.The increase of the nature saturation deficit of Pugionium cornutum （L.） Gaertn.seedlings was observed under mild drought stress conditions,and the nature saturation deficit under moderate and severe conditions were 0.32 percent point and 54.2 percent point higher than that of control, respectively.With the aggravation of drought stress,the available free water content of Pugionium cornutum （L.） Gaertn. leaves was gradually decreased.Under mild and moderate drought stress conditions,the tendency of the decrease was relatively slow,and the available free water content was 8.9 percent point and 15.2 percent point less than that of control,respectively. However,under severe drought stress conditions,a significant reduction of available free water content was observed （P〈0.01）.The irreducible water of leaves of Pugionium cornutum （L.） Gaertn.seedlings was gradually increased.Under mild drought stress conditions, the irreducible water was significantly higher than that of control （P〈0.05）. However,no significant increase of irreducible water were observed under moderate and severe drought stress conditions（P〉0.05）.