| In the suburban of Beijing, a planting system “winter wheat-summer maize” is very common and crop residues incorporation is also popular. At the same time, N-fertilizer is used more than needed. In this paper, effects of crop residues incorporation and N-fertilizer on the summer maize seed filling and yield were studied. There were two factors, straw covering and no-straw covering. “No N-fertilizer, traditional N-fertilizer and optimized N-fertilizer” were the three levels designed. The results showed the seed volume of summer maize was improved by 17.38%19.69%, the period with high filling rate was prolonged by 57days,the yield was improved obviously because of straw and N-fertilizer use. Treatment “crop residues incorporation +optimized N-fertilizer”, was the best treatment whose yield was 7 385.1 kg/hm2and the highest among the six treatments. And the yield characteristics and yield components were studied which indicated that in the treatment “crop residues incorporation + optimized N-fertilizer”, seeds per ear was 598.19, and increased by 27.3%. In the treatment “crop residues incorporation +traditional N-fertilizer”, the 1000-seed weight was 239.75 g, which showed that “crop residues incorporation +optimized N-fertilizer”was the best approach to improv the yield of summer maize in the suburban of Beijing. |