Abstract:Specific leaf area(SLA, leaf area per unit dry mass)and Leaf dry matter content(LDMC, the ratio of leaf dry mass to fresh mass)as important variables in plant ecology, scientists research leaves traits mainly by the SLA and LDMC because they are associated with many critical aspects of plant growth and surviva1in different environment and they are can be simple measured. In this paper, the typical plants Nitraria tangutorum leaves was chosen as research materials, and according to years average precipitation of Dengkou and plant growth regulation, designed the two precipitation enhancement period (May to July, August to September), each precipitation enhancement period set two rain enhancement gradients (72.5mm/ year(50%),145mm/years (100%)), conducted the artificial simulation of precipitation enhancement to natural Nitraria tangutorum shrubs. We examined changes of SLA and LDMC of Nitraria tangutorum leaves during growing season in 2012 and 2013. The results showed that the artificially simulated precipitation (B/C/D/E treatment)added SLA and LDMC of Nitraria tangutorum leaves, at the same simulated precipitation period, effect of SLA and LDMC in 100% treatment was greater than 50% treatment, however, there was no significant difference between tow treatments in the same simulated precipitation period; SLA response to simulated precipitation in the early stage of the growing season was obviously, on the contrary, LDMC was sensitive to simulated precipitation in the late stage of the growing season. The same treatment of two years, the net added(precipitation treatments minus contrast) of SLA and LDMC of leaves in 2012 was greater than 2013;the relationship between SLA and LDMC in 2012 was significantly negatively correlated, but in 2013 it was not significantly correlated although the relationship was negatively correlated. In the context of future in rainfall creased, SLA and LDMC of Nitraria tangutorum leaves had strong ability of adapt and coordination to rainfall increased and it cloud adapted to the environment by changing leaf traits in the different growing seasons.