Objective: To study the scavenging effect of active ingredient compatibility from Chinese herbal on carcinogens such as radicals and polycyclic aromatic hydrocarbons in vitro. Method: The active ingredient formula of Chinese herbal were composed of ginkgo biloba extract(GBE)

total flavonoids of glycyrrhiza(TFG)

total flavonoids of epimedium (TFE)

astragalosides(AST) and tatal saponins of ophiopogon (TSO). Uniform design and comprehensive weight coefficient method was used to analyze the effect of the formula on cavenging polycyclic aromatic hydrocarbons and radicals in vitro. Result: According to the comprehensive action

the pharmacodynamic actions of five active ingredient formula was stronger than any single ingredient. The best effect was in the ratio of GBE 3.144 g·L-1

TFG 0.8 g·L-1

TFE 0.024 g·L-1

AST 0.036 g·L-1 and TSO 0.036 g·L-1. The optimum proportion was 33∶131∶1∶1.5∶1. Conclusion: Active ingredient compatibility of Chinese herbal could strengthen the scavenging effect of single active ingredients on carcinogens such as radicals and polycyclic aromatic hydrocarbons

which may play the role of reducing the damage of carcinogens on human being.