Abstract: According to the results of physiological indexes of the Populus euphraticn’ leaves and the data of groundwater depth from 2001 to 2007, some conclusions could be drawn primarily: After water conveyance, some physiological indexes of the P. euphraticn’ leaves obviously changed with the groundwater depth and the relieve of water-stress intensity, and these changes presented certain correlations with the varying of groundwater depth. In the 10 parameters, chlorophyll content, soluble sugar and abscisic acid (ABA) had high correlations with the groundwater depth of the growth sites, showing that these parameters could be used as indicators for manifesting the extent of water stress of P. euphraticn. The indexes of malondialdehyde (MDA) and cytokinin (CTK) could be regarded as reference indexes of the extent of water stress which P. euphraticn suffering from. While, the physiological indexes of proline (Pro), superoxide dismutase (SOD), peroxidase (POD), gibberellin (GA₃) and indoleacetic acid (IAA) were not sensitive to the change of the groundwater depth.

Key words: groundwater depth, physiological indexes, Populus euphraticn, the lower reaches of Tarim River