Abstract: The study aim to investigate the N releasing characteristics and biological effects of several slow/ controlled release fertilizers in light sierozems in Ningxia, and find the suitable combination of materials for slow/controlled releasing. A pot experiment was conducted under the same N, P, K nutrients input to study the effect of five fertilizer treatments on the growth, N uptake and utilization of spring maize, and simultaneously investigate N releasing characteristics of these slow/controlled release fertilizers in soil. The results indicated that the plant height, shoot biomass and total biomass of spring maize more or less increased after applying slow/controlled release fertilizers in contrast to treatment of no N fertilizer, and shoot N uptake, root N uptake and total N uptake also significantly increased in treatments of slow/controlled release fertilizers; N use efficiency ranged from 33.9%-39.7% in these treatments of slow/controlled release fertilizers, which increased by 2.4%-8.2% compared with that of balanced fertilization of NPK (31.5%). There were about 65 days of N releasing in soil for self-developed slow/controlled releasing fertilizers, and the N releasing peak was before and after 32 days; however, N releasing peak was before and after 17 days for commodity coated urea, there was still high N releasing after 65 days in soil. Therefore, in contrast to commodity coated urea, the N releasing days should be extended in self-developed slow/controlled release fertilizers, but they could supply enough N for spring maize during the early growing period.