【Objective】This study aims to investigate the effects of various nitrogen treatments on the growth, photosynthesis, and yield of Lycium barbarum under elevated atmospheric CO₂ concentrations. The objective is to optimize the production and adaptive cultivation of L. barbarum. 【Method】One-year-old cuttings of L. barbarum ‘Ningqi-1’ were used as experimental material. Two CO₂ concentrations were tested: ambient (T1, (380±20) μmol/mol) and elevated (T2, (760±20) μmol/mol), using an open-top chamber control system. Additionally, three nitrogen levels were applied per kilogram of soil: 0 g/kg (N0), 0.8 g/kg (N1) and 1.6 g/kg (N2). Measurements of plant morphology, photosynthetic indices, daily net photosynthetic rates, and yield were taken at 45, 60, 75 and 90 days.【Result】Over time, the combination of elevated CO₂ and nitrogen treatments enhanced the stem diameter, shoot length, thickness, and stomatal conductance of ‘Ningqi-1’, while inhibited the stomatal limit. The chlorophyll content initially increased, then decreased, and later increased again. The T2N1 treatment performs the best during each assessment period. The net photosynthetic rate of “Ningqi-1” treated with T2 for 60, 75 and 90 days was significantly higher than that of T1, with increases of 87.72%, 68.33% and 67.56%, respectively, reaching rates of 25.24, 28.33, and 28.25 μmol/(m²·s),respectively (P<0.01). With elevated CO₂ levels, the transpiration rate of “Ningqi-1” significantly increased during the N1 treatment across 45, 60, 75, 90 days but significantly decreased during the N2 treatment at 45 and 60 days, recording 2.84 and 2.41 mmol/(m²·s), respectively. Additionally, stomatal conductance of “Ningqi-1” significantly increased from 75 to 90 days (P<0.05). Water use efficiency significantly increased from 75 to 90 days post-N1 treatment, reaching 10.68 and 9.34 g/kg, while the stomatal limit remained low. Increasing CO₂ concentrations reduced the correlation among stomatal limitation and variables such as shoot length, thickness, chlorophyll content, and yield per plant. Conversely, it enhanced the correlation between transpiration rate, net photosynthetic rate, water use efficiency, and the aforementioned plant traits in “Ningqi-1.” Based on the CO₂ concentration model for daily net photosynthetic rate, the optimal theoretical nitrogen application rate for “Ningqi-1” was estimated at 0.875 g/kg (soil). The yield per plant under this regime was slightly higher than that of the T1N1 treatment.【Conclusion】The N1 nitrogen treatment under elevated CO₂ conditions effectively increased the stem diameter, shoot thickness, chlorophyll content, net photosynthetic rate, stomatal conductance, and water use efficiency of “Ningqi-1,” while reduced the stomatal limit. This treatment also sustained higher yields and mitigated the adverse effects of increased CO₂ levels, making it a more suitable option for cultivation in environments with higher CO₂ concentrations.