Abstract: The experiment results have shown that the diffusion inside the tea leaves is a rate－determining step in the water extraction of constituents from the tea.It was not due to the resistance of the layer.The infusion parameters of tea constituents (such as caffeine,theaflavins) could be defermined by kinetic equation(rate of infusion,activation energy),partition constant and diffusion coefficient in the state of infusion equilibrium.

Key words:  , Tea Constituents Infusion Kinetics Mechanism；