In order to study the effect of nitrogen(N)fertilizer application rates in winter rape season on N supply and yield of summer maize under rape-maize rotation system，Chuanyou 36 and Zhongyu 3 were used as experimental materials，and three N fertilizer treatments:40% reduction in conventional nitrogen application rate(108 kg/hm²)，20% reduction in conventional nitrogen application rate(144 kg/hm²)and conventional nitrogen application rate(180 kg/hm²)，named as N1，N2 and N3，respectively，were carried out in the winter rape growing season of 2018～2019 and 2019～2020. The results showed that the alkaline N content in 0～20 and 20～40 cm soil layers of the following summer maize season decreased with the nitrogen reduction in the winter rape season，especially in 0～20 cm soil layer.The alkaline N content of N1 treatment was significantly lower than that of N2 and N3 treatments，while the difference between N2 and N3 treatments was not significant.The amount of N accumulation in maize plants decreased with nitrogen reduction in winter rape season，and there were significant differences among the treatments，while the transfer rate of nitrogen to the grain showed an upward trend.The amount of N accumulation in maize grain and yield were higher those in N2 and N3 treatments.In 2018～2019，the amount of N accumulation of N2 was significantly higher than that of N1 and N3 treatments by 6.43% and 3.95%，and yield was significantly higher by 8.28% and 4.72%，respectively.In 2019～2020，the amount of N accumulation of N2 and N3 treatments were significantly higher than that of N1 treatment by 5.73% and 7.94%，and yield were significantly higher by 14.27% and 15.89%，respectively.When the nitrogen application rate was 20% reduction in the conventional nitrogen application rate in winter rape season，the annual nitrogen reduction and efficiency increase of the rape-maize rotation system could be achieved，and the N utilization by the maize grain could be effectively improved.