Abstract: To determine the optimum nitrogen amount in a wheat-corn cropping system with long-term straw returning, a split plot experiment was carried out, non-straw returning and total straw returning were used as the main factor, nitrogen amounts (0, 90, 180, 270 and 360 kg N/hm2) were used as cofactors. The effect of long-term straw returning combining with nitrogen fertilizer application on the growth, yield and quality of winter wheat in a wheat-corn cropping system was studied. Results showed that, at the same nitrogen amount, straw returning increased foliar area, photosynthetic rate, chlorophyll contents, ground dry matter amount and yield of the wheat. As nitrogen amount increasing, chlorophyll content generally increased, but the leaf area, ground dry matter amount, the number of spikes and spike grains and yield increased initially and then decreased. The contents of protein and wet gluten were enhanced along with the increasing nitrogen amount. 270 and 360 kg N/hm2 treatments caused salt damage and reduced the yield of wheat. Straw returning plus the application of 180 kg N/hm2 promoted the growth, yield and quality of winter wheat. The simulation analysis indicated that the optimum nitrogen amount was 216.11 kg/hm2 under the total straw returning model.