Abstract: In order to analyze the effect of weather condition on crop growth quantitatively, crop growth model WOFOST is used to calculate the climate suitability of winter wheat. Simulate the crop growth during 2007-2009 growing season in 3 representative sites in North China, and take the result of 2007-2008 growing season as standard, then compare other corresponding period’s biomass and take the ratio as winter wheat’s climate suitability then compare the value with traditional statistical algorithm. Results showed that, the suitability calculated by the model had a better positive correlation with the actual yield, R2=0.603 and passed the 0.05 confidence level test, the algorithm could be used to evaluate winter wheat’s climate suitability.