Abstract: In this paper, using winter wheat yield and meteorological data during 1981-2009 in the Weishan County, Shandong Province, our purpose is to study the impact of meteorological factors (rainfall, sunshine, temperature) on yield. Firstly, analyzing meteorological data simply, and checking the relationship between meteorological factors, we found that there was strong negative correlation between rainfall and sunshine; the authors built the meteorological conception model, and dealt with the relationship between variables, using the orthogonal polynomial method to solve the Fisher integral regression model. The results showed that, rainfall was conducive to increase the yield in the future, the yield increased by 1.65 kg/hm2 to 2.25 kg/hm2 if the rainfall increased 1 mm more than in the normal month. Higher temperature was beneficial to the yield, the yield increased by 272.4 kg/hm2 if the temperature increased 1℃ higher. In winter period, lighting was conducive to the yield; the yield increased by 135.3 kg/hm2 to 166.5 kg/hm2 if the lighting increased 1 hour more. During the turning green period and jointing stage, rainfall in March and April promotes the yield increasing, the yield increased by 4.95 kg/hm2 and 4.2 kg/hm2 if the rainfall increased 1 mm. In this paper, the meteorological yield coefficient could explain how meteorological factors influence the yield of winter wheat. This laid the foundation of methodology for the forecasting winter wheat yield in the future.