Abstract: Based on the daily average and minimum air temperature data of 70 meteorological stations in the Northeast China from 1961 to 2006,the spatial variations of first date of the temperature ≥10℃,the first frost date,days of growing period and the accumulated temperature ≥10℃ at 80% of the assuredness probability over last 46 years for the different maize varieties were analyzed. The results showed that climatic resources for maize increased significantly in 2001-2006 compared to the 1960s. First date of the temperature ≥10℃ was 2-10 days earlier except in Mohe of Daxing'an Mountains. First frost date was 5-10 days later except in Daxing'an Mountains where it became 5-20 days earlier,and in Xiaoxing'an Mountains and Liaoning Province it was not significantly. The days of the growing period increased about 10 days except in the northern part of Daxing'an Mountains where it decreased 10 days and in the northern part of Liaoning Province it was not significantly. The accumulated temperature ≥10℃ increased by 200-400℃except in Daxing'an Mountains and Xiaoxing'an Mountains where it was not significantly. In the fitting districts for maize growing,planting date came earlier 2-10 days than the 1960s. Distribution line of the different maize varieties moved obviously toward east and north in 2001-2006,extremely early-maturing varieties were planted in Xiaoxing'an Mountains,while the medium-maturing varieties and medially late-maturing varieties were planted in Sanjiang Plain,and late-maturing variety was planted in the south part of Songnen Plain,and early-maturing variety could be planted some areas in Changbai Mountains which were lack of heat condition for maize growing before 2000.

Key words: Northeast China, Northeast China, Climatic resources for maize, Planting date, Variety distribution