We explored the response of photosyntheticCO₂ response curve and fruit medicinal components of Lycium ruthenicum cultivated in arid areas to nitrogen(urea, N, 46%) application. The experiment had five different N application rates ［0(CK), 50, N2:100, 150 and 200 g·strain^-1］. The net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), water use efficiency (WUE), intercellular CO₂ concentration (C_i) and the contents of total polysaccharides, total flavonoids, anthocyanins, proanthocyanidins in the fruit were measured, and the parameters including carboxylation rate (η), maximum net photosynthesis rate (P_nmax), photorespiration rate (R_p), CO₂ compensation point (CCP) and CO₂ saturation point (CSP) were obtained by fitting a rightangle hyperbolic correction model. The results showed as follows: (1) appropriate N application rate had certain effects on η, P_nmax, R_p, CCP and CSP in leaves of L. ruthenicum. When N application rate was 100 g·strain^-1, η and R_p were the largest, and CCP was the smallest. When N application rate was 100~150 g·strain^-1, CSP was the largest. When N application rate was 150-200 g·strain^-1, P_nmax was the largest. (2) Appropriate N application rate had certain effects on the contents of the main medicinal components in fruits of L. ruthenicum. When N application rate was 200 g·strain^-1, the total polysaccharide content was the largest. The total flavonoid content was the largest when N application rate was 150-200 g·strain^-1. The anthocyanin content was the largest when N application rate was 50-150 g·strain^-1. The proanthocyanidin content was the largest when N application rate was 100-200 g·strain^-1. For comprehensive consideration, the best L. ruthenicum planting conditions in arid areas are the optimum of η, R_p, CCP, CSP, contents of polysaccharides and total flavonoids when N application rate at 100-150 g·plant^-1, and the optimum of P_nmax, contents of anthocyanins and procyanidins when N application rate at 150-200 g·plant^-1per year.