[Objective] The object of this study is to investigate the variation trend of crop water requirement and its correlation with climatic factors

so as to provide references for decision making in crop irrigation and drainage. [Methods] The crop water requirement and irrigation requirement of winter wheat in Shihezi region were calculated based on evapotranspiration calculation approach recommended by United Nations FAO and crop coefficient from 1961 to 2012. The variation trend and its climatic causes were analyzed for the crop water requirement and irrigation of winter wheat. [Results] (1) The crop water requirement of winter wheat showed a significant decreasing trend

and the greatest increase occurred at the overwintering and turning green stage with a rate of 2.65 mm/10 a. Winter wheat required the most water at the jointing to heading stage (130.23 mm). (2) In contrast

irrigation water requirement of winter wheat at different growth stages showed a decreasing trend with a rate of -3.11 mm/10 a. The irrigation water requirement of winter wheat was the most at the jointing to heading stage (88.65 mm). (3) Climatic factors such as precipitation

temperature

relative humid

sunshine duration

water pressure

wind speed

showed a strong correlation with the crop water requirement and irrigation requirement of winter wheat. Extremely significant correlation was found between precipitation and the crop water requirement and irrigation requirement of winter wheat. [Conclusion] Although water requirement of winter wheat increased during the past 52 years

the irrigation requirement of winter wheat showed a decreasing trend

which caused by the increase of precipitation.