In order to explore the effective measures that improve nitrogen utilization in irrigation silting soils of Ningxia,a water immersion test and pot experiment was conducted to study on N releasing characteristics of three kinds of controlledrelease fertilizer,respectively;and the effects of five fertilizer treatments on rice yield and nitrogen use efficiency under the same N，P，K nutrients input were investigated．The coated controlledrelease fertilizer by polyurethane was the tested material.The results indicated that there were very similar tendencies of accumulative N releasing ratio for the two kinds of controlledrelease fertilizer(CRF1,CRF2)in water(25℃).The initial releasing rate in 24 h of CRF1 and CRF2 treatment were 3.54% and 2.28%(≤15%),and accumulative N releasing ratios in 28 d were 33.17% and 30.58%(≤80%)，which were accorded with national standards of slow release fertilizers．Compared to the NPK treatment,the rice grain yield of the CRF2 treatment was 31.21 g/pot which was increased by 10.44%,the aboveground N uptake was 150.89 kg/hm2 which was increased by 10.46%,the nitrogen use efficiency was 36.64% which was increased of 5.49 percentage points.The peaks of soil NH+4N,NO-3N and mineral N content in different fertilizer treatments were happened at about 15 d of rice growth,and then declined to some extent respectively.The controlledrelease fertilizer treatments were decreased slowly,and the corresponding N releasing periods were greater than 75 d.Due to adding nitrification inhibitor dicyandiamide,the CRF2 treatment could maintain the highest soil NO-3N(the 45th day:99.41 mg/kg)and mineral N content(the 45th day:104.46 mg/kg)in 45 days after transplanting of rice,and the highest soil NH+4N content(the 60th day:4.03 mg/kg)in 60 days,which satisfied the demand of nitrogen for the critical period of rice growth and ensured the grain yield.