Effect of different planting density and nitrogen application on spring corn yield and biomass produc-tion was studied in the paper. Results indicated that under the middle-high density, the output realized mainlythrough the harvest ear of number, and grain number per ear was key factor affected the yield. Nitrogen insufficientand excessive caused the abortion occurrence and bald-tip ears increased. Seed development was promoted and thenumber of grains per ear increased at moderate nitrogen of 220 kg/hm², so the yield increased.