The effects of single basal application of controlled release blended fertilizer on the yield，nitrogen use efficiency and leaf enzyme activities of summer maize were explored to provide technical support for reducing fertilizer application and increasing efficiency.A field experiment was carried out on the summer maize variety “mingkeyu 77”.No nitrogen(CK)，conventional nitrogen(U100)and 3 controlled release blended fertilizer levels(CBB100，CBB90 and CBB80，which denotes 0，10% and 20% reduction of N rate based on U100，respectively)were employed in this experiment.The yield of summer maize，nitrogen use efficiency，key enzyme activities of leaves nitrogen metabolism，economic benefits and soil inorganic nitrogen dynamics were analyzed and investigated.The results showed that the release of controlled release nitrogen in the field was mainly concentrated in the early and middle period of summer maize，and the cumulative release rate of nitrogen was 56.2% and 86.2%，respectively，at jointing and harvesting.Compared with U100，the yield of summer maize was increased by -2.64%，4.41% and 9.41%，the agronomic utilization rate of nitrogen was increased by -0.03，2.99 and 4.45 kg·kg-1，the utilization rate of nitrogen was increased by 16.6%～29.5%，the partial productivity of nitrogen fertilizer was increased by 4.45～10.25 kg·kg-1，and net income per hectare(excluding fertilizer input)was increased by -108，816 and 1442 yuan in CBB80，CBB90 and CBB100 treatment，respectively.The activities of nitrate reductase，glutamine synthetase，glutamate synthetase and glutamate dehydrogenase in leaves of summer maize were significantly increased by nitrogen application.Compared with U100，the activities of leaves in CBB90 and CBB100 were increased，with significant difference in glutamine synthetase activities，but there was no significant difference in other parameters between nitrogen application treatments.According to the factors of summer maize yield，nitrogen utilization rate，economic benefit of fertilization and residual soil nitrogen，the effect of no nitrogen reduction by controlled-release blended fertilizer was the best.