To investigate the effects of postponed nitrogen application on nitrogen metabolism，yield，and quality of sesame，a field experiment was conducted under the condition of consistent total pure nitrogen application:basal nitrogen application of 120 kg/hm²(T1)，basal nitrogen application of 60 kg/hm²+seedling stage topdressing of 60 kg/hm²(T2)，basal nitrogen application of 40 kg/hm² + seedling stage topdressing of 40 kg/hm² + bud stage topdressing of 40 kg/hm²(T3)，with no nitrogen fertilizer applied as the control(CK)to study the effect of nitrogen fertilizer transfer on sesame nitrogen metabolism，yield，and quality.The results showed that postponed nitrogen application significantly enhanced the activity of key enzymes in nitrogen metabolism in sesame leaves，increased the content of free amino acids and soluble proteins in sesame leaves，yield，and improved sesame quality.Among them，T3 treatment had the best effect.During the initial，peak，and final flowering stages，the activities of nitrate reductase(NR)，glutamine synthase(GS)，and glutamate synthase(GOGAT)were significantly higher than other treatments.NR activity increased by 6.40%，35.42%，74.78%，12.04%，30.67%，38.19%，and 9.39%，16.64%，21.31%，respectively，compared to T2，T1，CK treatments.GS activity increased by 9.16%，24.36%，39.98%，6.02%，18.57%，24.65%，and 14.64%，23.07%，28.03%，respectively，compared to T2，T1，CK treatments.The activity of GOGAT increased by 14.38%，24.88%，48.38%，15.22%，27.67%，59.56%，and 31.53%，60.56%，67.09%，respectively，compared to T2，T1，CK treatments.Compared with CK，T1，T2 treatments，T3 treatment significantly increased the number of capsules per plant by 72.88%，38.91%，18.80%，respectively；The number of capsules per plant increased by 24.70%，14.44%，2.96%，respectively；The thousand grain weight increased significantly by 19.35%，13.41%，8.03%，respectively；The yield increased significantly by 142.07%，68.93%，23.82%，respectively；The protein content increased significantly by 28.00%，7.59%，9.27%，and the crude fat content increased by 7.69%，5.08%，4.07%，respectively.Related analysis showed that during the peak and final flowering stages，there was a significant or extremely significant positive correlation between yield，protein content，crude fat content，and NR，GS，and GOGAT activities.In the eastern Henan region，a fertilization plan of 40 kg/hm² of basal nitrogen fertilizer，40 kg/hm² of seedling stage topdressing，and 40 kg/hm² of bud stage topdressing can be used for highyield and high-quality cultivation of sesame in this area.