Based on field experiment,the influence of controlled release urea (CRU) application on soil inorganic nitrogen distribution,nitrogen uptake and use characteristics of spring maize (Zea mays L.) was analyzed to provide theoretical basis and technical support for high-efficiency utilization of nitrogen fertilizer and high-yield maize in the southern mountain area of Ningxia. Xianyu 698 was used as experimental material. Five treatments that including No nitrogen was applied as the control (CK),conventional nitrogen supply UR (100% Urea (U),1/3 U base application,1/3 U flare opening period application),CRU1 (1/3 CRU + 1/3 U base application,1/3 U flare opening period application),CRU2 (2/3 CRU + 1/3 U base application),and CRU3 (100% CRU base application) were designed to explore the effects of CRU input on soil inorganic nitrogen distribution,nitrogen uptake,nitrogen use efficiency and yield of maize. The results showed that the soil nitrate nitrogen and ammonia nitrogen content in the mid-late stage of maize with the CRU treatments was significantly increased compared with those of UR treatment,with the highest increase in CRU2 treatment. CRU input could improve the yield and nitrogen utilization of spring maize. Compared with UR,the average yield of spring maize increased by 0.67 t/hm²,the nitrogen partial factor productivity (NPFP) increased by 2.92 kg/kg,and the nitrogen use efficiency (NUE) increased by 6.02%. Compared with CRU1 and CRU3 treatments,the yield,NPFP,and NUE in CRU2 treatment within two years were significantly increased by 0.10 t/hm² and 0.53 t/hm²,0.30 kg/kg and 2.23 kg/kg,2.49% and 9.44%,respectively,indicating that the positive responses of yield,NPFP,and NUE to CRU2 in all CRU treatments. Comprehensively,under reasonable distribution conditions,the blending of UR and CRU had a significant effect on increasing the soil nutrient supply and nitrogen absorption in spring maize. Therefore,we suggested that 2/3 CRU+1/3 U base application for rain-fed maize in Southern Ningxia.