In this study

a field experiment was performed by using split-plot to investigate the effects of supplemental irrigation and nitrogen fertilizer application on winter wheat yield

nitrogen absorption and distribution. Based on measured soil moisture content in 0—40 cm soil layers at the jointing stage of wheat

three irrigation levels were designed in main plots

which could make the moisture content of target soil reach 60%（W1）

70%（W2）

and 80%（W3）. In the sub-plots

three nitrogen levels were designed

0 kg/hm2 (N0)

195 kg/hm2 (N195)

and 255 kg/hm2 (N255). The results were as follows: (1) Supplemental irrigation and nitrogen application had significant effects on plant height and leaf area of winter wheat. For the same irrigation treatments

plant height and leaf area of followed the order of N255＞N195＞N0（p＜0.05），under the same nitrogen application treatments

plant height and leaf area in W2（569.4 m3/hm2） and W3（873.45 m3/hm2） were significantly higher than that in W1（265.2 m3/hm2）（p＜0.05）

but the differences between W2 and W3 were not significant（p＞0.05）

indicating that excessive nitrogen application and irrigation had no significant influence on the plant height and leaf area of winter wheat. (2) Under the same nitrogen application treatments

the threshold response to wheat yield was observed under different ratios of N application and irrigation

the highest yield (8 500 kg/hm2) was reached under the N195 and W2 (569.4 m3/hm2). (3) During the maturity stage of winter wheat

under W2 and W3

nitrogen accumulation under N255 was significantly lower than that under N195（p＜0.05）; especially for N255

nitrogen application had no significant influence on nitrogen accumulation

indicating that appropriate irrigation and nitrogen application could increase’s ability to absorb nitrogen. (4) Though wheat nitrogen absorption increased with t increasing amount of water irrigation

nitrogen distribution proportion in the grain was reduced. Considering the growth status of winter wheat and nitrogen risk status

a N level of 195 kg/hm2 and an irrigation rate of 70% field capacity (569.4 m3/hm2) is suitable for water and fertilizer application in this region.