[Objective] Objectives of this study were to investigate the impacts of two major lactic acid bacteria (L. homohiochii XJ-L1 and L. buchneri XJ-L2) on the microbial communities and flavor quality of Chinese Maotai-flavor liquor. [Methods] Bacteriostatic tests in vitro and mixed culture fermentation were carried out to investigate the interactions between main lactic acid bacteria and the other major microorganisms during fermentation. [Results] L. buchneri XJ-L2 could inhibit the growth of three Bacillus strains (B. amyloliquefaciens XJ-B1, B. subtilis XJ-B2, B. licheniformis XJ-B3), five mold strains (A. oryzae XJ-M1, A. niger XJ-M2, A. flavus XJ-M3, A. albicans XJ-M4, R. oryzae XJ-M5) and two yeasts (Sc. pombe XJ-Y4, G. candidum XJ-Y5). L. homohiochii XJ-L1 and L. buchneri XJ-L2 could promote the growth of three main yeasts (S. cerevisiae XJ-Y1, Z. bailii XJ-Y2, P. galeiformis XJ-Y3), and benefited for the production of acids, alcohols, esters etc. [Conclusion] The two main lactic acid bacteria, L. homohiochii XJ-L1 and L. buchneri XJ-L2, could maintain the ecological status of the main yeasts in the fermentation process through promoting the growth of three main yeasts and inhibiting bacillus, mold and few yeasts (L. buchneri XJ-L2 was more obvious). In addition, lactic acid bacteria affected the formation of acids, alcohols, esters and other flavor compounds and benefited for Maotai-flavor liquor fermentation. The appropriate proportion of lactic acid bacteria could enhance the balance of fermentation microflora. It is significant for the aroma production of Chinese Maotai-flavor liquor.