Abstract:High-throughput sequencing was performed for the fermented grains in the first-round stacking fermentation of Maotai-flavor Baijiu to reveal the microbial diversity. The volatile compounds in fermented grains were determined by high performance liquid chromatography and gas chromatography. The relationship between dominant microbial taxa and flavor compounds was analyzed. The results showed that during the firstround stacking fermentation， the dominant bacterial genera included Bɑcillus （15.65%）， unclɑssified_Bɑcillɑceɑe_2 （26.88%）， unclɑssified_Thermoɑctinomycetɑceɑe_1 （25.94%）， and Acetobɑcter （28.80%）； the dominant fungal genera included Thermomyces （60.58%）， Aspergillus （15.50%）， Pichiɑ （64.48%）， Kɑzɑchstɑniɑ（15.20%）， and Issɑtchenkiɑ （11.76%）. There were 33 positive correlations between bacteria and were 44 positive correlations between fungi during the fermentation process. Most microbial genera were positively correlated. During the stacking fermentation process， 31 flavor compounds were identified in the fermented grains. The content of acetic acid gradually increased with the extension of stacking time， reaching a maximum of 607.18 mg/L. Among the esters， ethyl linoleate （27.36 mg/L） and ethyl lactate （16.70 mg/L） had higher contents.Among the alcohols， 1，2-propanediol had the highest content of 137.51 mg/L during the fermentation process. Among the dominant microbial taxa， Pichiɑ had positive correlations with ethyl lactate and ethyl oleate； Acetobɑcter had negative correlations with isovaleric acid and 1，2-propanediol； Stɑphylococcus and Kɑzɑchstɑniɑ had negative correlations with ethyl oleate， butyl caproate， and ethyl lactate and a positive correlation with acetic acid.