According to the data of experiment from October, 198S to June, 1986, the paper analyzed and determined the optimum water consumption from the relationship be-ween yield and water consumption. It also multievaluated the different treatments from grain yields, straw yields, water use efficiencies and irrigation costs and determined the optimum treatment The results obtained from the two methods are the same. The law of water consumption during the different stages for winter wheat is analyzed and it is useful to water management of crop field and climatical evaluation.