Under the background of global change,the variation of precipitation pattern might affect vegetation dynamics in arid zone.Nitraria tangutorumshrub land,which is one of the typical desert vegetation in Minqin County,Gansu Province,was chose to study the effect of precipitation variation on vegetation dynamics.Through the successive four years of artificial rain enrichment scenario,soil moisture of the N.tangutorumshrub land,leaf traits index and morphological characteristics of branches of N.tangutorum were measured in2011 under different simulated rainfall gradients(increased0%,25%,50%,75%and100%of mean annual precipitation,respectively).The cumulative effects of different treatments on the physiological and ecological characteristics of N.tangutorum were studied.The results showed that soil moisture of the N.tangutorumshrub land shallow layer was obvious improved,soil moisture of 10 cm layer in the increased 75%and 100%rainfall treatment was significantly increased;leaf water potential,net photosynthetic rate (Pn),transpiration rate(Tr),stomatal conductance(Gs),specific leaf area(SLA),mass-based leaf nitrogen (Nmass),and the growth of the length and basal diameter of N.tangutorum branch were increased with increasing rainfall,leaf water potential and indexes of leaf functional traits on the first day after the 100% rainfall treatment were significantly greater than that in the increased 0%rainfall treatment;SLA and Nmass were increased with increasing rainfall,and not reached significant level;The growth of the length and basal diameter of N.tangutorum branch were increased with increasing rainfall,and in the increased 75% and 100%rainfall treatment was significantly greater than that in the increased 0% rainfall treatment,their differences were 64.57%、66.63%and 48.71%、67.54%,respectively.It was suggest that N.tangutorum through adaptive strategies of internal physiological and external forms to promote its growth.