Climate change, mainly caused by elevated atmospheric CO₂ concentrations, affects plant growth and physiology, and much attention has been paid to this subject recently. Global warming will affect the quantity and geographical distribution of precipitation. In western China, water and shortages in precipitation are key factors for plant growth and survival. Global warming will result in increased evaporation of water in soil, which will cause some areas to experience more severe droughts. High air temperatures increase drought stress in plants, which in turn accelerates the damage caused by high temperatures. For these reasons, the physiological and morphological responses of plants to global warming have become a critical issue. Lycium barbarum is an economic forest tree species in Ningxia, China, and is unique because of the high quality of its fruit, which contains nutrients and microelements, especially polysaccharides, taurine, and carotenoids. Lycium barbarum shows resistance to drought, saline and alkaline soils, and to cold temperatures; furthermore, it has the ability to adapt to a wide range of ecological conditions, which makes it a significant ecological, social, and economic asset for the Ningxia region. Lycium barbarum has been widely planted and has become one of the major agricultural crops in Ningxia. However, the response of L. barbarum to elevated temperatures and water shortages under climate change remain unknown. Here, we hypothesized that the stressors resulting from elevated temperature and drought would not affect photosynthesis in L. barbarum. We subjected 1-y-old L. barbarum seedlings to the following controlled conditions: open-top chambers to simulate different temperature conditions (ambient temperature, AT; elevated temperature, ET = AT+2.5-3.7 ℃); a combination of three different soil water contents (control group, W1, approximately 70%-75% of maximum soil water content; moderate drought stress, W2, approximately 50%-55% of maximum soil water content; and severe drought stress, W3, approximately 35%-40% of maximum soil water content). We then studied the effects of elevated temperature and drought stress on photosynthesis of L. barbarum by testing the photosynthetic and fluorescence indices of seedlings. Our results showed that under elevated temperature conditions, net photosynthetic rates of seedlings in the moderate and severe drought stress treatments were reduced by 17.5% and 48.9%, respectively, that average stomatal conductance was reduced by 3.9%, and that water use efficiency was 57.8% that of the control group. Therefore, elevated temperature and soil drought stress reduced net photosynthetic rates, stomatal conductance, and intercellular CO₂ concentrations of the seedlings and increased transpiration rates, which reduced water utilization efficiency in the seedlings. The elevated temperature and soil drought stress reduced the optical energy transfer efficiency of the Photosystem Ⅱ activity center in leaves, which resulted in the reduced photosynthetic efficiency in L. barbarum seedlings. These results indicate that elevated temperature would increase the negative effects of drought stress on the net photosynthetic rate in the seedlings. In summary, the elevated temperature and drought stress reduced photosynthesis in L. barbarum.