Abstract: A field experiment was conducted to study the effects of reduced nitrogen application and supplemental irrigation on the light environment, photosynthetic characteristics and yield components in high-yield wheat population. The treatments included three irrigation schedules [no irrigation (W₁), medium irrigation (W₂, the soil relative water content of 70%±5% after jointing stage), well-irrigation (W₃, the soil relative water content of 85%±5% after jointing stage)] and three nitrogen application levels [no nitrogen (N₁), reduced nitrogen (N₂,195 kg N·hm^-2), high nitrogen (N₃, 270 kg N·hm^-2)]. The results indicated that the N₂W₂ treatment significantly improved the light environment of high-yield wheat populations, the photosynthetically active radiation (PAR) and the light transmission rate at the region of 20-30 cm canopy increased by 34.5% and 10.8%, respectively, when compared with the high nitrogen-supplementary water treatments (N₃W₂, N₃W₃). The leaf area index (LAI) of N₂W₂ was the highest among all treatments tested, which decreased slowly at grain filling stage, and the period with higher LAI value (>7.6) was 3-4 days longer than that of high-nitrogen and non-nitrogen treatments, as well as, the leaf photosynthetic potential was increased by 9.7% on average. Under the treatments of N₂W₂ and N₂W₃, the photosynthetic rate (P_n) was relatively higher at grain-filling stage, while the difference was not significant compared with the treatment of N₃W₂. The apparent quantum yield in flag leaves of N₂W₂ reached 0.1 μmol CO₂·m^-2·s^-1, P_n value kept on the level of 27.692 μmol CO₂·m^-2·s^-1 and the light compensation point (LCP) was relatively lower, which demonstrated a stronger photosynthetic productivity. The grain yield of N₂W₂ was the highest among all treatments.