Abstract: The photosynthesis charateristics of Artemisia ordosica and Caragana korshinskii in the artificial vegetation of Shapotou area were studied in this paper.Nine parameters were measured and calculated,including photo flux density,air temperature,air relative humidity,net photosynthesis rate,stomatal conductance,intercellular CO2 concentration,stomatal limitation value,transpiration rate and water use efficiency.The results showed that there were two-peaks in diurnal curves of photosynthesis in plant leave.The first peak appeared at 9:00a.m.and the second at 17:00.These were the response of desert plants to the arid environmental factors,for example,strong photo flux density,high temperature and low humidity.Net photosynthesis rates of the two kinds of shrubs were mainly affected by stomatal factors from 9:00to 15:00,but by non-stomatal factors from 7:00a.m.to 9:00.and from 17:00 to 19:00.The net photosynthesis and water use efficiency of Artemisia ordosica was obviously higher than those of Caragana korshinskii.All of above made it clear that Artemisia ordosica was much more adaptable to the drought environment in Shapotou Area than Caragana korshinskii.