[Objective] To analyze yeast community structure and its influence on brewing during the fermentation process of Chinese Maotai-flavour liquor. [Methods] The yeast community in the fifth round (higher yield and quality of the liquor) and the seventh round of fermentation process (lower yield and quality of the liquor) were analyzed using denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR (RT-qPCR). The metabolic components in the fermented grains were investigated through headspace-solid phase microextraction gas chromatograph-mass apectrometer (HS-SPME-GC-MS) and high performance liquid chromatography (HPLC). Finally, the effects of yeast communities on the yield and quality of Maotai-flavor liquor were analyzed. [Results] At least nine yeasts were detected in the fermented grains, including Issatchenkia orientalis, Torulaspora delbrueckii, Pichia galeiformis, Schizosaccharomyces pombe, Galactomyces geotrichum, Trichosporon asahii, Zygosaccharomyces bailii, Saccharomyces cerevisiae and Pichia fabianii. Among them, G. geotrichum and S. cerevisiae was dominant yeasts of the fifth round, while the other two yeast, I. orientalis and Z. bailii, were also advantage in seventh round and Sc. pombe was not detected. In addition, five kinds of yeasts declined significantly during latter period of the seventh round fermentation process, but the yeast community structure during the fifth round was relatively more stable. The total yeasts during the early stage of the fifth round fermentation is 2?5 times more than the seventh round’s, while ethanol content of fifth round fermented grains was 2.45 times as higher as the seventh’s at the end of fermentation. Besides, volatile metabolic component of fermented grains was rich in species. The content of esters of the fifth round was remarkably higher than the seventh round, while organic acids and fusel oils were lower than the seventh round. [Conclusion] During Maotai-flvour liquor brewing process, there is rich diversity in yeast species, and the dynamics of yeast community structure affect liquor’s yield and quality obviously, which provides the basis for the study of Maotai-flavour liquor brewing mechanism.