Abstract: Post-fermentation was performed on the old green tea to investigate the variation of the quality ingredients and aroma components of tea. The results showed that the contents of polyphenols, catechins decreased by 52.87% and 87.12% respectively after post-fermentation, simple catechins decreased by80.88%, ester catechins decreased by 90.66% and among that EGCE decreased by 92.7%, however the content of GA increased by 888.72%. The contents of free amino acids and chlorophyll decreased by 53.67%and 27.6% respectively after post-fermentation, but the contents of water soluble sugar, water-soluble pectin, theaflavins, thearubigins and theabrown increased by 53.4%, 50.15%, 33.33%, 15.26% and 129.3% respectively.In addition the contents of old green tea aroma components increased by 235.80% after post-fermentation.The content of Phytol and 3-methyl-2-butenyl was the highest of all the aroma components in the different tea.However after post-fermentation, 1-methyl-Naphthalene and 1, 3-dimethyl-5- (1-methylethyl) -Benzene was not be discovered, but the new components e.g. geraniol and benzocycloheptatriene were discovered.Linalool-L and their oxidation products had also taken profound changes during post-fermentation. Overall, after post-fermentation, the characteristic of Sichuan dark tea was formation.