As part of global climate change, variation in precipitation in arid ecosystems is leading to plant adaptation in water use strategies; significant interspecific differences in responses will change the plant composition of desert communities. This integrated study on the ecophysiological and individual morphological scales investigated the response, acclimation, and adaptation of a native dominant desert shrub, Haloxylon ammodendron, to variation in water conditions. The experiments were carried out under three manipulated precipitation treatments (natural, double and no precipitation), in its original habitat on the southern periphery of Gurbantonggut Desert , during the growing season in 2005. Changes in its photosynthesis, transpiration, leaf water potential, water use efficiency, above-ground biomass accumulation, and root distribution were examined and compared under the contrasting precipitation treatments. The results indicate that its efficient morphological adjustment, combined with strong stomatal control, contributes to its maintenance of photosynthesis and acclimation to variation in precipitation. On account of its positive responses to increased precipitation, H. ammodendron is predicted to succeed in interspecific competition in a future, moister habitat.