The observation data from 104 meteorological stations over the period of 1961 2010 and the winter wheat data from 17 agrometeorological stations over the period of 1981 2010 in Sichuan Basin were used to estimate the water requirement of winter wheat in each of its growth stages and provide a guidance for agricultural water consumption in Sichuan Basin and to analyze the water budget condition during the winter wheat-growing season with the crop coefficient approach and the Penman-Monteith equation. The results revealed that the precipitation throughout the growing period of winter wheat (from sowing to maturity) increased in some areas but decreased in other areas from 1961 to 2010. The water requirement and water deficit from sowing to maturity decreased in the main. The water requirement decreased from sowing to flowering stage, but increased or decreased from flowering to maturity stage. The water deficit in each growth stage declined from 1961 to 2010. The precipitation during the period of winter wheat growth, from sowing to maturity, could not meet the water requirement of the crop in all the 5 regions studied, especially from jointing to flowering stages of the plants. A comparison of the water budget conditions of the representative stations of various regions showed that the most serious water deficit happened in the peripheral mountainous regions of Sichuan Basin.