Abstract:To investigate the changes in microbial community distribution and chemical composition during fermentation of Ampelopsis grossedentata leaves，fermented Ampelopsis grossedentata leaves were used as samples for microbial DNA extraction，PCR amplification，sequencing library construction，high-throughput sequencing data analysis，and identification of microbial community distribution. Based on the determination of the contents of flavonoids，polyphenols，proteins，amino acids，soluble sugars，and water-soluble extract，UPLC-MS/MS was applied to determine the changes in flavonoid and polyphenol compounds during fermentation. Comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry （GC×GC-TOFMS）system was usedto analyze the changes in volatile components before and after fermentation. The results showed that at the genus level，the dominant microbial communities in Ampelopsis grossedentata leaves were Lactobacillus，Pediococcus，and Bifidobacterium during fermentation. The contents of flavonoids，polyphenols，soluble sugars，and water-soluble extracts reached the maximum at 60 h and then decreased gradually during fermentation. Among the five flavonoid compounds （dihydromyricetin，myricitrin，piceatannol，myricetin，and quercetin），their contents had minor changes and strong stability. Among the eight polyphenol compounds （epigallocatechin gallate，gallocatechin，epigallocatechin，etc.），the content of epigallocatechin gallate （EGCG） decreased，while that epigallocatechin （EGC） increased，and the contents of the other polyphenol compounds remained basically unchanged. The contents of protein and amino acids decreased gradually throughout fermentation period. The main volatile components produced during fermentation included terpenes，alcohols，aldehydes，esters，and ketones，which contributed to the characteristic aromas of wood，floral，and mint notes；the key aroma components were methyl salicylate and caryophyllene.