Using no nitrogen fertilizer(N0)as the control group,the field experiments with conventional nitrogen fertilizer(N100),two treatments of nitrogen reduction(reducing 20%and 40%),and two treatments of arbuscular mycor-rhizal(AM)fungi were conducted to investigate the combined effects of nitrogen reduction and AM fungi treatments on the invasion and development of AM fungi,maize yield traits,nitrogen metabolism-related enzyme activity,and nitrogen fertilizer absorption and utilization efficiency.The results showed that,the 20%nitrogen reduction treat-ment can promote the infection and development of AM fungi,while 40%nitrogen reduction treatment was the next.Compared to the N0 treatment,the kernel yield,ear rows and grain number per row increased under both the 20%ni-trogen reduction treatment and the 20%nitrogen reduction+AM fungi treatment.The maize nitrogen agronomic effi-ciency(NAE)and the nitrogen recovery efficiency(NRE)were the highest under the 20%nitrogen reduction+AM fun-gi treatment.The nitrate reductase(NR),nitrite reductase(NiR),glutamine synthetase(GS),and glutamate synthase(GOGAT)in maize roots possessed a higher activity under the 20%nitrogen reduction+AM fungi treatment when comparing to the N0 treatment.The activity of NR,NiR,GS,GOGAT increased by 140.4%-147.4%,96.1%-117.9%,131.5%-183.1%,and 122.8%-128.9%,respectively.Meanwhile,both the 20%nitrogen reduction treat-ment and the 20%nitrogen reduction+AM fungi treatment significantly enhanced nitrogen absorption in the above-ground and underground parts of maize plant throughout different growth stages,which is an effective measure to im-prove maize yield and reduce nitrogen fertilizer application.