Abstract: Precipitation is the chief limiting factor for the processes and functions of desert ecosystems, and the plant species are extremely sensitive to precipitation variations during growing seasons. Artificial rainfall simulation experiments were conducted upon desert plants of different life forms to assess the responses of plant growth to rainfall changes. According to the rainfall amount in the growing season of 2013, rainfall amount was reduced by 25% or 50%, or increased by 25%, 50% or 100%, with natural rainfall as the control. The results showed that precipitation changes in growing season affected the growth of plants and the primary productivity, and significant differences were found in the response to rainfall amount between plants of varying life forms. Reduced precipitation slowed down the new branch growth of Caragana korshinskii and Artemisia ordosica, though the change was not significant. Rainfall increase by 25% did not significantly promote the growth of C. korshinskii and A. ordosica. Rainfall increase by 50% significantly promoted the new branch growth of A. ordosica, but not C. korshinskii. Between May and July, rainfall increase by 100% significantly promoted the new branch growth of A. ordosica, and so was it for C. korshinskii between June and July. The aboveground biomass of annual herbaceous plants significantly linearly increased with rainfall amount in the growing season and plant height significantly decreased only in plots with rainfall reduction by 50%.

Key words: metabolic enzymes, protective enzymes, chemical control period, quality., peanut, yield