The turnable pan coating method was used to produce three kinds of coated urea by polyurethane，taking polyurethane as the main coating ingredient，and paraffin wax，modified kaolin，dicyandiamide(calcium oxide)as the mixture ingredients.A water immersion test and pot experiment was carried out to study on N releasing characteristics of three kinds of independent development of coated urea by polyurethane，respectively; and the effects of six fertilizer treatments on the growth，N uptake and utilization of spring maize under the same N，P，K nutrients input were investigated.The results indicated that there were very similar tendencies of accumulative N releasing ratio of three kinds of independent development of coated urea by polyurethane in water(25℃).The initial releasing rate in 24 h were 2.04%~3.64%(≤15%)，and accumulative N releasing ratios in 28 d were 29.88%~34.80%(≤80%)，which were accorded with national standards of slow release fertilizers.N uptake and utilization of spring maize in treatments independent development of coated urea by polyurethane was significantly improved compared to treatment NPK.N use efficiencies of these coated urea by polyurethane were ranged from 32.5%~40.0%.there was no significant difference from commodity coated urea(19.5%).The peaks of soil mineral N content in treatments independent development of coated urea by polyurethane and commodity coated urea were happened before and after 28 and 15 d，and the corresponding N releasing periods were greater than 70 and 60 d，respectively.During the growing period of spring maize(within 91 d)，soil mineral N content in treatments independent development of coated urea by polyurethane was always higher than those in treatments commodity coated urea and NPK.Therefore，in contrast to commodity coated urea and NPK fertilizers，N releasing days was even longer and N supplying was rather enough during the early growing period of spring maize in these independent development of coated urea by polyurethane.