Abstract: 【Objective】To analyze the relationship between the growth and development of mechanical grain harvesting varieties of spring maize and the dominant temperature factors in different growth stages in northern China,and to reveal the matching mechanism between the growth and development of mechanical grain harvesting varieties of spring maize and thermal resources,so as to provide a theoretical basis for the selection and promotion of mechanical grain harvesting varieties of spring maize in areas with different thermal conditions.【Methods】 The late maturing varieties,early maturing varieties and mechanical grain harvesting varieties of spring maize suitable for local growing conditions were used as the experimental materials. The late maturing varieties were Zhengdan 958（ZD958）,early maturing varieties were Demeiya No.1（DMY1）,and grain harvesting varieties were J6518,C1563 and Dika 159. The variety×density tests were conducted in Lingdong warm-cool area（EXM）,Lingnan warm area（SXM）,Yanshan hilly area（NYH）and West Liaohe plain area（WLR）with different thermal conditions in Inner Mongolia. The effects of temperature factors on growth periods before and after anthesis,matter accumulation and grain yield of different types of spring maize varieties were analyzed.【Results】The daily average temperature（T_a）and daily range（T_r）were the core temperature factors affecting the matter accumulation of mechanical grain harvesting spring maize before and after anthesis. In areas with limited heat,the proportion of growth days before and after anthesis were 5.0∶5.0;in areas with sufficient heat,the growth days before anthesis were longer than that after anthesis,and the proportion of growth days before and after anthesis were 4.5∶5.5. The relationship between pre-anthesis T_a and pre-anthesis matter accumulation accorded with the linear law of y=7.08x-133.6. For each increase of T_a by 0.1 ℃,the pre-anthesis biomass was increased by 0.71 t/hm². The relationship between post-anthesis T_r and post-anthesis matter accumulation accorded with the linear law of y=7.94x-82.68. For each increase of T_r by 0.1 ℃,the post-anthesis matter accumulation increased by 0.79 t/hm².【Conclusion】When the proportions of growth and development days before and after anthesis of mechanical grain harvesting varieties of spring maize were 4.5-5.0∶5.0-5.5,higher pre-anthesis T_a and higher post-anthesis T_r were the premise to achieve high yield and high efficiency.

Key words: Spring maize, Temperature factor, Accumulated temperature, Mechanical grain harvesting variety, Matter accumulation, Yield