Traditional vinegar brewed by traditional technologies was a kind of functional food with special flavor. The brewing process of vinegar was controlled empirically and it has a complicated structure of microflora formed by spontaneous enrichment of microorganisms in raw materials. After inheritance and improvement for thousands of years, the traditional vinegar brewing technology has formed a stable structure of microflora by a long-term domestication of microorganisms. The reason of special flavor of different vinegars may be due to the structure of microbial communities. Recently, many researchers showed great interest on the mechanism of traditional vinegar brewing. The aim of the present review is to introduce the latest research progress of the diversity of microbial communities and functional studies of main microorganisms in traditional vinegar fermentation process.