Synergistic effect of vitamin C (VC) and Hanzhongxianhao tea polyphenols on in vitro antioxidant capacity of was investigated by DPPH· and ABTS⁺· assays. Antibacterial activity of the mixtures of tea polyphenols and VC against Escherichia coli was analyzed by broth dilution method and Oxford cup method. The mixtures of tea polyphenols and VC [m (tea polyphenols)∶ m(VC)=1∶1,1∶2,2∶1] exhibited strong ability to scavenge DPPH·, and their EC₅₀ values were lower than those of tea polyphenols and VC. Moreover, the more VC the mixture contained, the lower EC₅₀ value was. EC₅₀ value of the mixture of tea polyphenols and VC [m (tea polyphenols)∶m(VC)=1∶1] for ABTS⁺· was slightly lower than that of VC. Mathematical model based on dose-effect relationship between antioxidant capacity and sample concentration possessed high goodness of fit. Minimum inhibitory concentrations against Escherichia coli of the mixtures of tea polyphenols and VC [m (tea polyphenols)∶m(VC)=1∶1,2∶1] were 38 and 46mg·mL-1. Antibacterial activity of the mixture of tea polyphenols and VC [m (tea polyphenols)∶m(VC)=2∶1] was higher than those of VC and tea polyphenols due to its relatively large diameter of inhibition zone. After tea polyphenols were mixed with special quantity of VC, their free radical-scavenging abilities were slightly improved and antibacterial activities were notably increased.