Abstract:Huanglv group germplasm is an important landrace and exhibits well adaption in China. Great effort had been taken in the improvement and innovation of Huanggai and Lvdahonggu germplasm by enriching favorable alleles or introducing exotic germplasm decent since 1980s and 1990s, which contributed a lot for maize hybrids breeding in our country. Mechanical grain harvesting is the inevitable trend of maize production, therefore, it’s essential to improve agronomic traits that related Mechanical grain harvesting, for example moisture content, lodging resistance and stalk rot resistance. In this study, both male and female parental European early-maturing inbred lines, UH004F and UH004M (UH004F: male, Hard-gained maize; UH004M: female, Iodent maize), were used to purposefully improve the mechanical grain harvest related traits of Huanglv group germplasm, and finally we got some nearly homozygous inbred lines(named after Huanglv-European lines, HE lines) by modified pedigree selection and recurrent selection. The major research is: (1) The days to tasseling, days to silking and growth period decreased and exhibited considerable early-maturity. Anthesis-to-Silking Interval (ASI), Plant height, Tassel length, Internode length above ear, Ear length, Kernel length and Seed production rate showed an increasing trend. While Ear height, Stalk diameter, Kernel row number, Ear diameter, Cob diameter and Kernels weight per ear exhibited a reversed trend. Meanwhile, we observed that the introgressive lines perform well on lodging and conversion resistance. In terms of Hundred kernels weight, all the improved subgroups except Chang7-2 subgroup have lower moisture content compared with unimproved subgroups. The tassel branch number ranged from 6 to 9 and did not show an unique trend before and after improvement. (2) The introgression of 25% and 50% European early-maturing hard-grained male parent population and European early-maturing Iodent female parent population into the progeny lines of Huanglv Group showed a certain trend in most traits, which mainly manifested in the earlier Days to tasseling, days to silking and growth period; the increase of ASI value, the increase of Plant height,, the decrease of Ear height, the increase of Tassel length, the increase of Tassel branch number and Stalk diameter, the elongation of Internode length above ear. The trend of Lodging rate, Ear length, Kernel row number, Ear diameter, Cob diameter, Hundred kernels weight, Kernels weight per ear, and Moisture at harvest were improved. All the other traits mentioned above were further enhanced when 50% of the male parent population was introduced into European early-maturing hard grain germplasm, which indicated that the male parent population contained favorable alleles controlling mechanical grain harvest traits which were more suitable for innovative improvement of Huanglv population. The early-maturity European germplasm contained excellent alleles suitable for mechanical grain harvest. The visible achievements on improvement of mechanical grain harvest traits could provide theoretical guidance for subsequent large-scale breeding and application of Huanglv population.