Abstract:The forecast elements were chosen from the data of field catches and rainfall of Gongzhuling,and the forecast targets were determined on the damage degrees and areas of outbreak of the yearly first generation adults and their next generation larvae of oriental armyworm,Mythimna separata(Walker),in Jilin province.The stepwise regression method was applied to study the forecast mathematic formula,and the computing,analysis,selecting,formation of polynomial regression equations and fitting of historical data were carry out by computer programs of Basic language.The forecast models of the spring generation oriental armyworm of Jilin province were put forward.