The grey correlation degree method was applied to study effects of climatic factors on maize yield in different ecological regions of Jilin Province. The results showed that the correlation degree of sunshine hours and accumulated temperature with maize yield was the closest in central region. The correlation degree of accumulated temperature and sunshine hours after anthesis and silking stage with maize yield was the closest in eastern region.The correlation degree of precipitation with maize yield was the closest in western region. Maize yield would in-crease with the increase of accumulated temperature in mid and eastern area, but it would decrease with the in-crease of accumulated temperature in western area. So, reasonable varieties should be selected and corresponding cultivation technology adopted to fully use natural resource.