Abstract: 【Objective】To screen out varieties suitable for mechanical grain harvesting in Warm -cool Area of the East of Daxing' Anling, and promote and application of maize mechanized grain harvesting technology.【Methods】From 2017 to 2019,a selection experiment of mechanical grain harvesting of maize was carried out in W arm-cool Area of the Fast of Daxing' Anling.The experiment was set a random block design ,and the growth period , station stalk period, yield , grain moisture content , grain crushing rate , grain damage rate of 70 maize varieties in 3 years were measured. 【Results】Only 14.3% of the varieties with grain moisture content≤25.0% in 3-year harvest period, and lack of varieties suitable for mechanical harvesting. Based on the two-way average method of grain moisture content and yield ,combined with mechanical grain harvesting traits, the varieties with high yield ,low grain moisture content , and conforming to mechanical grain harvest traits were selected: Demeiya No.1,J6518,Lihe 228 and Renhe 319. September was an important period for maize to mature and seeds dehydrated in this region.At this time , the rainfall distribution, rainfall amount, rainfall days, air humidity and sunshine hours were the main factors affecting maize grain dehydration. Grain crushing rate , grain damage rate and grain moisture content were extremely significantly positive correlation (P<0.01);at harvest, the average grain moisture content of 70 varieties was 29.0% in 3 years (22.2% to 35.8%), the grain moisture content was generally high. The grain crushing rate was the lowest when thegrain moisture content was 23.0% -25.0%(≤2.0%).【Conclusion】Grain moisture content was the key to the quality of maize grain harvest,2 300 C active accumulative temperature was a suitable for maize mechanical grain harvesting in Warm-cool Area of the East of Daxing' Anling.

Key words: Warm- cool Area of the East of Daxing' Anling, Maize, Variety, Grain moisture content, Mechanical grain harvest quality