Abstract: The relations among water,fertilizer and yield of winter wheat are analyzed by the experiment data from Changwu arid highland,Shaanxi Province. The results show that the relations between water use efficiency or soil water use ratio and crop yield are close.Water use efficiency and soil water use ratio are affected by the method of fertilization, the type and amount of fertilizer. Paying attention to rational use of N,P₂O₅ is a good way to improve water use efficiency and soil water use ratio.In view of effect of N/P on soil water use, N is advantageous to increase water use efficiency,and P₂O₅ is good to improving soil water use ratio and increasing rate-used of deep soil water.