Variation of the functional microbes was quantitatively analyzed during the acetic acid fermentation process of Zhenjiang aromatic vinegar.Real-time quantitative PCR(RT-qPCR) was applied to quantitatively analyze the variation of bacteria,fungi,Acetobacter,Lactobacillus and Saccharomyces during the acetic acid fermentation process in this study.Results showed that the biomass of bacteria,Acetobacter and Lactobacillus increased rapidly in the initial stage of fermentation(day 1-7),and reached the maximum on the 6th,7th and 4th day with the biomass were 3.37×1011,1.14×1010 and 3.37×1011 copies/g dry grains respectively,which followed by a gradually decent to a certain level with the fermentation performed.The biomass of fungi and Saccharomyces showed little change in the initial stage of fermentation,while the biomass of fungi decreased gradually to 7.59×104 copies/g dry grains from day 7 to day 18,and the biomass of Saccharomyces decreased rapidly to zero from day 8 to day 12.