Abstract: The cluster analysis is used to zone agroclimatic in Sanjiang plain region, based on the zoning result representative forecasting sites were selected and model for qualitative and quantitative forecast of yields of corn, soybean and wheat were established, including the model of the year's harvest tendency, stepwise regression periodical component model and multilevel recursion forecasting model. Statistical test and forecasting result show that the models can give accurate forecast of the yield the three crops significantly.