Abstract: In order to determine the optimum application amount of controlled-release nitrogen fertilizer on summer maize, a field experiment was conducted to study the effects of different blend ratios of controlled-release and conventional N-fertilizer and the treatment of reducing 20% nitrogen fertilizer on the yield, nitrogen accumulation, use efficiency of fertilization and agronomic efficiency of summer maize. The results showed that treatments of total and reducing controlled-release N-fertilizer both increased maize nitrogen accumulation compared with conventional N-fertilizer under the same application rates. Nitrogen accumulation increased by 16.46%, 39.02%, 20.97% and 8.22%, respectively, by treatments of 100% coated urea, 70% coated urea, 50% coated urea and 50% coated urea with reducing nitrogen in full ripe stage. There was no significant effect on maize nitrogen accumulation trend with treatments of total and reducing controlled-release N-fertilizer. Treatments of total and reducing controlled-release N-fertilizer could increase the use efficiency of N, P, K and agronomic efficiency significantly. Compared with the conventional N-fertilizer treatment, treatments of total and reducing controlled-release N-fertilizer could increase the yield of maize significantly, the treatment of 70% controlled-release urea had the highest yield of maize, and the rate of growth was 12.33%.