Abstract:According to the rules of development of poplar canker, caused by Dothiorella gregaria Sacc., the multivariant linear stepwise regression prediction model was established using method of multivatiant statistics with factors as disease index (Dis), pathogens (F1, F2, F3), collect temperature(CT), ratio of temperature to relative humidity (TH), ratio of temperature to raina ll(TR) and ratio of relative humidity to rainfall (HR):Dis=19.0-F31/2.8+0.1F1+0.0015(F2)3+4.15TH-CT1/0.042-0.4HR+1.5TR.The disease index of the following a month could be predicted with this equation what was proved to be reliable by examination using actual disease index obtained in the survey.