Abstract:In order to clarify the changes of sensory quality and components during the fermentation of Suancha，the changes of tea polyphenols，free amino acids，water extract，water-solubility sugar and catechins in raw tea stage，middle stage and final stage of Suancha fermentation were determined by ultraviolet spectrophotometry and high performance liquid chromatography.The results showed that：as the fermentation proceeded，the contents of moisture，water-solubility sugar and epigallocatechin gallate，first decreased and then increased significantly （P ＜0.05）；the contents of dry matter，gallic acid and epigallic catechin first increased and then decreased significantly （P＜0.05）；the contents of water extract，free amino acids，tea polyphenols and total acids increased significantly （P ＜0.05）；and the pH value，catechin，epicatechin，epicatechin gallate，caffeine and total catechin decreased significantly （P ＜0.05）.With the fermentation proceeding，the brightness value L*and redness value a*of Suancha liquid color increased significantly （P＜0.05），the yellowness value b*decreased significantly（P＜0.05），and the total color value E*ab had significant difference （P ＜0.05）.During fermentation，the overall sensory evaluation quality of Suancha increased significantly.Through the comparative analysis of chemical composition，color difference and sensory changes in the fermentation process of Suancha，the scientific basis for the drink，protection and inheritance of Suancha was provided.