In order to understand the effects of warming on temperature conditions during various growing periods of winter wheat, the changes of monthly averaged temperature and the changing trends of the dates of critical developmental stages and averaged temperatures during the growing periods of winter wheat in North China Plain were analyzed based on the meteorological and phonological data collected from agrometeorological observation stations from 1981 to 2010 and warming experiments in the region. The results showed that there was a significant warming trend in October, December and between February and June during the growing season in the Plain. Furthermore, the average temperature in February exhibited the maximum linear tendency rate of temperature increasing among the months. Climate warming significantly increased the average temperatures over overwintering and the period from reviving to jointing stage of winter wheat. At the same time, the warming caused the jointing to maturity dates of winter wheat significantly advanced. However, the average temperatures over two periods did not show the same increase trend as the corresponding monthly averaged temperatures. The temperature condition over the period before winter was stable because of delayed sowing, an insignificant change in average temperature during the period from jointing to maturity was attributed to advance of developmental stages and local climatic characteristics of seasonal variation. In addition, climate warming would lead to more advance of post-winter developmental stages of winter wheat, which would keep the average temperature over the period less change.