Abstract: Based on the meteorological and crop data collected by the 78 meteorological stations in Anhui Province from 1961 to 2009, water demands and precipitation in the field-growth periods of single-cropping rice and winter wheat are discussed. The results indicate that the water demand of single-cropping rice during the field-growth period gradually increased from north to south, but the water supply in most areas of Yanhuai and southen Huaihe valley was sufficient in most years because of the sufficient precipitation. On the contrary, the water demand of winter wheat during the whole-growth period gradually decreased from north to south because of the comprehensive influence of temperature, wind speed and relative humidity in the winter-half-year and the precipitation was also generally insufficient. The water supply could not meet the demand of winter wheat in main production areas, and especially during the key water demand period.

Key words: single-cropping rice, winter wheat, growth period, key water demand period, water supply and demand