Abstract: By using fuzzy mathematics, the suitability functions of temperature, precipitation and sunshine time for winter wheat were established in Hebei Province to estimate the climatic suitability to the growth and development of winter wheat quantitatively. The weight coefficient was determined by the unitary integral return method to calculate the climatic suitability of the temperature, precipitation and sunshine time during growing period of winter wheat. The results indicated that the subjection degree for the temperature and sunshine was relative high, but for the precipitation was low with large variable extents. These explained that the temperature and sunshine were able to satisfy the growth and development of winter wheat. The lack of the natural precipitation was a limited factor for the formation of the winter wheat yield.

Key words: Winter wheat, Winter wheat, Meteorological factors, Quantitatively estimate, Fuzzy mathematics