Abstract: Based on the meteorological data and yields of the main grain crops in Tianshui,the relationship between the agro-meteorological disasters and the food grain crop yields was analyzed by using the mathematical models.The result showed that the main agro-meteorological disasters which influenced the grain yields of winter wheat and maize were the spring drought,early summer drought,steady rain in hot summer,drought in the last autumn,and unreasonable cold in early spring.The mathematical models for the climate yield of winter wheat and maize were built up based on the intensity of the agro-meteorological disasters.

Key words: Agro-meteorological disaster, Agro-meteorological disaster, Food crop, Yield