Abstract:The kinds and contents of free and bound volatile substances in Lichuan black tea and Enshi green tea, which are unique to Enshi, Hubei province, Wuling area, were studied by headspace solid-phase microextraction technology combined with gas chromatography-mass spectrometry. A total of 52 volatile compounds were detected in Lichuan black tea, including 36 free aroma compounds and 25 bound aroma compounds. Among them, 9 compounds were both detected in free and bound samples. While, a total of 56 volatile compounds was detected in Enshi green tea, including 15 free forms and 45 bound forms. Among them, there were 4 identical compounds. Meanwhile, the odor activity values were analyzed in two different teas. Aldehydes, alcohols and esters were the most valuable components contributed to the flavor profile of Lichuan black tea. Aldehydes, alcohols and olefins were the most valuable components contributed to the flavor profile of Enshi green tea. The results showed that geraniol and caprylic aldehyde were the main aroma substances in free forms of Lichuan black tea. Methyl salicylate, α-citral and linalool were the major aromatic components in bound forms. The octanal and limonene were the major aroma components for free forms in Enshi green tea. And the linalool and naphthalene were the main aroma components in bound forms. Fruity and floral aroma were the main aroma characteristics of Lichuan black tea, fruity and chemical odor were the major characteristics of Enshi green tea. The phenols and carboxylic acids in the free volatile components of Lichuan black tea and Enshi green tea were significantly different, and phenols and ketones in the bound volatile components were quite different. This study hoped to provide a reference for elaborating the composition of tea aroma and the generation of flavor substances, and at the same time, it would provide references for the deep processing and quality control of Lichuan black tea and Enshi green tea.