Abstract:The active components in hot aqueous extracts of 12 types of tea in Guangxi were identified and their antioxidant activities were determined.The active components of the tea extracts i.e.total flavonoids，total polyphenols，total polysaccharide，catechin，and epicatechin were analyzed.The scavenging activities of DPPH，ABTS+free radical and ferric ion reducing antioxidant power （FRAP）were determined to evaluate the antioxidant activities of the tea extracts in vitro.The correlation between the active components and antioxidant activities of the tea extracts was evaluated.The content of total polyphenols was relatively high in green tea and white tea，and was the highest in Sanjiangchun tea.The content of total flavonoids in black tea was greater than that in green and white tea，and was the highest in Meihong tea.The total polysaccharide content of green tea was relatively high，and was the highest in Xiaoyezhongxiangcha.The contents of catechin in Dongpoxianming and Wuniuzao green tea were significantly higher than those of other samples.However，catechin was not detected in black tea，except for Meihong.The contents of epicatechin in green tea and white tea were higher than that of black tea.Green tea and white tea displayed higher scavenging activities for DPPH，ABTS+free radical and higher FRAP than black tea.Total contents of polyphenols，polysaccharide，and epicatechin were positively correlated with free radical scavenging activities.The correlation coefficient was high.However，the correlation coefficient between total flavonoids and catechins and free radical scavenging activities was poor and even negatively correlated.In particular，the contents of total polyphenols，catechins，and epicatechins in green tea extract were higher，and the antioxidant activity was better compared to the other extracts.The content of total flavonoids in black tea was higher，but the contents of total polyphenols and catechin，and the antioxidant activity were lower than the values of green tea and white tea.