Due to climate change and heavy human activities, the precipitation and groundwater at the southern edge of the Gurbantunggut desert have significantly changed, which would affect the water use strategy of local plants. In this study, Haloxylon ammodendron, which is the constructive species in the southern edge of the Gurbantunggut desert, was taken as the study object. A consecutive investigation on seed germination, meteorological factors, aboveground height, belowground depth and plant biomass was carried out until the establishment of plant, to reveal its growth traits and adaptability during the whole establishment process. The results showed that diebacks of the assimilating branches in drought period could maintain the balance between water supply of roots and water consumption of the assimilating organs. This morphological adjustment ensured the photosynthetic ability of survival organs. Furthermore, the allocation of more photosynthates toward roots could ensure H. ammodendron survival during drought and recovering when water conditions become better.