Based on the weather data in the period of seedtime for winter wheat from 1961 to 2003 in the Zhumadian, Henan Province, a correlation analysis is made. The result shows that the temperature of conventional seedtime in the southern area of Henan Province gradually rises. The suitable seedtime for winter wheat is gradually postponed. Rainfall during the period of conventional seedtime has decreased. The conclusion is that the output of suitable late seeding winter wheat will be increased.