The Tarim River, located in central Xinjiang Uygur Autonomous Region, is situated north of the Taklimakana Desert. A reduction in groundwater levels and a concomitant increase in soil salinity have reduced vegetation in lower reaches of the river. Tamarix ramosissima is one of the dominant plant species in this riparian system. This species provides a buffer between the desert and riparian zone and contributes significantly to ecosystem function and maintenance of biodiversity. Thus, an understanding of how T. ramosissima responds to changes in groundwater levels and soil salinity is necessary for ecological and economic management of this riparian system. We found a positive correlation (Pearson Correlation Coefficient = 0.80305) between T. ramosissima Abscisic Acid (ABA) and groundwater levels; there was a negative correlation between ABA and soil salt levels (Pearson Correlation Coefficient = 0.00961). From these ABA groundwater/salinity relationships we concluded that 3.12 m subsurface groundwater level and 0.96 g/L soil salt can limit the normal growth and development of T. ramosissima; greater than 5.59 m subsurface groundwater level and 1.61g/L soil salt will strongly impede the normal development of T. ramosissima. So, we should take into account the resistance of plants to environmental stressors such as drought and salinity to keep the level of salt and groundwater on both sides of the main river within a range in which trees, shrubs, and herbs can grow well and perform various ecological functions. Such conservation practices not only avoid the waste of water resources, but will also contribute to efficient artificial water-recharge, helping to maintain the Tarim River riparian zone and promote “green corridor” maintenance.