Abstract: The southern edge of the Taklimakan Desert is one of the most serious desertification areas in China. Natural vegetation type is scarce in desert-oasis transition zone，and [Alhagi sparsifolia，][Tamarix ramosissima] and [Karelinia caspica] are the main constructive species and dominant plants. Therefore, it is necessary to introduce some new species which have strong drought resistance, high water use efficiency and high economic values. Three kinds of three-year-old sand fixing plants，Xanthoceras sorbifolia（X） Bunge，[Hedysarum scoparium] Fisch.et Mey（H），and [Berberis thunbergii] cv. Atropurpurea（B） were taken as the experimental materials in this experiment, their physio-ecological responses in the period from persistent drought to short-time re-watering were investigated in this area. The purpose of this paper was to understand physiological and ecological responses of the three introduction plants to soil moisture changes. The results showed that re-watering after drought stress due to the increase of soil moisture results in increase in chla，chlb，chl and chla/b of H and B significantly, while the four indexes of X reduce. Soil moisture changes had relatively larger impact on the chla. Total chlorophyll of H and B increased by 46.13%，60.26%，but X decreased by 21.32%. MDA and SS contents of the three plants did not decrease but a significant increase and both index of X increased dramatically，206.32% and 199.40% respectively; while the Pro content was inordinately lower and B had a big reduction, which is 87.86%. The morning and noon water potential of three species declined with the increase of soil moisture；morning potential reduction of three plants were 115.25%，100.59%，90.97% and morning potential reduction of three plants were 86.92%，5.74%，11.20% respectively. Especially，water potential of H and B changed relatively smaller, which showed that signs of water deficit of the two plants was not significant. Compared to the three plants，X and H had a strong resistance to drought，and B was more sensitive to soil moisture change. On the one hand，the innovative point of our experiment is to select three plants under natural conditions which experienced drought and sporadic rainfall and compare the physiological and biochemical index and water potential changes of three plants to analyze the drought resistance and environmental adaptability of them. On the other hand，our experiment has a good application value. The results provide theoretical references for introduced plants adaptability and plant species selection in shelterbelt construction in the research area.

Key words: re-watering, physiological and biochemical indexes, water potential, Taklimakan Desert