To clarify the generation distribution changes of the Asian corn borer, Ostrinia furnacalis (Guenee), in different areas of Jilin Province, the adult oviposition period and larval development of O. furnacalis were systematically investigated in 28 counties in the eastern, central, and western ecoregions of Jilin Province. The results showed that the egg deposition period of eastern ecoregion had one peak period, and the generation number of eastern ecoregion was still one, while pupae were observed in Yitong and Ji'an, and the generation numbers of Yitong and Ji an were one or one and a half; the egg deposition period of central ecoregion had two peak periods, and the generation number of central ecoregion had changed from one and a half to two, while the third generation larvae were observed in Shuangliao and Lishu, and the generation numbers of Shuangliao and Lishu were two or two and a half; the egg deposition period of western ecoregion had two peak periods, and the generation number of western ecoregion was still two, while the third generation larvae were observed in Tongyu, and the generation numbers of Tongyu were two or two and a half. The results indicated that the generation numbers of O. furnacalis in Jilin Province showed an increasing trend with global warming.