Objective: To study the influence of the combined administration of Trichosanthis Fructus and Aconiti Radix Cocta at different dose or ratio on thier expectorant and antitussive effects. Method: The uniform design method was used based on two factors and seven levels to investigate phenolsulfonphthalein excretion and number of cough in mice and the influence of the combined administration of Trichosanthis Fructus and Aconiti Radix Cocta at different dose or ratio on theirexpectorant and antitussive effects. A demonstration test was conducted by choosing significant ratio and dose. Result: Combined administration of Trichosanthis Fructus and Aconiti Radix Cocta at most ratios can increase the phenolsulfonphthalein excretion in mice. According to the regression analysis

Trichosanthis Fructus had an expectorant effect in mice. And the expectorant effect of the combined administrationof Trichosanthis Fructus and Aconiti Radix Cocta was not lower than that of the single administration of Trichosanthis Fructus in mice. At the rate of 1:2 between Trichosanthis Fructus and Aconiti Radix Cocta

the expectorant effect of the combined administrationwas almost the worst. Both Trichosanthis Fructus and Aconiti Radix Cocta at all ratios decreased the times of cough. According to the regression analysis

the combined administration of Trichosanthis Fructus and Aconiti Radix Cocta had good antitussive effect

but they had not an interactive effect with each other. Conclusion: The combined administration of Trichosanthis Fructus and Aconiti Radix Cocta could decrease the expectorant effect of Trichosanthis Fructus

but had no effect on the antitussive effect of Trichosanthis Fructus.