A field experiment was conducted to study the effects of Urea Ammonium Nitrate Solution(UAN)on winterwheatyield，N use efficiency and N balance in Hebei plain area of low and medium yields. The result showed that grainyield increased significantly by Nfertilization，which was mainly due to the increase of grain number per panicle. With theapplication of UAN and Urea under the same Nlevel，the grain yield had no significant difference. The yield of 80% UANtreatment was slightly reduced as compared with that of 100% UAN treatment，but not significant. With the same Nlevel，Nuse efficiency had no significant differences among UAN and Urea treatments. While the N agronomy efficiency，N partialproductivity and N use efficiency were all high in 80% UANtreatment，and the N partial productivity was 20.6% higher than that of OPT-UAN treatment. Compared with Urea treatment under the same Nlevel，UAN treatment showed lower mineralN residual in soil but no significant N uptake inplant，thus leaded to the higher N loss in the entire soil -crop system. Inconclusion，the application effects of UAN on winter wheat were similar to that of urea in thestudy，and the UAN synergistic agent needs further research.