The positive response of Populus euphraticato the change of groundwater level was analyzed by monitoring different ecological parameters of P.euphraticaon the three typical transects along the lower reaches of Tarim River.The results show that the growth of P.euphraticariparian forests correlated closely with the groundwater depth.The groundwater has been recharged and risen significantly after ten times of water diversion

and also the vitality of P.euphraticaimproved to different extent as the result of groundwaterrecharging. P.euphraticadrought-stress intensified with the rising of groundwater depth.As a result

the response of P.euphraticato ecological water diversion decreased gradually away from the river channel

and along the river

this response reduced gradually from the upper section to the lower section.Although P. euphraticaseedlings have appeared sporadically in the wet area near the two sides of riverbank

the present water-recharging scheme is difficult to realize the reproduction and renewal of P.euphraticain large areas.