Objective: To study the effect of the combined administration of Aconiti Radix Cocta and Ampelopsis Radix at different dose or ratio on formalin-induced licking time in mice. Method: The uniform design method was used based on two factors and seven levels to investigate licking time of formalin-intraplantar model at two phases

meanwhile

a demonstration test was conducted by choosing significant ratio and dose. Result: The combined administration of Aconiti Radix Cocta and Ampelopsis Radix availably reduced the licking time of two phases. Neither Radix ampelopsis nor Aconiti Radix Cocta used alone had the analgesic effect by regression analysis. There was the synergistic effect between Ampelopsis Radix and Aconiti Radix Cocta

and Ampelopsis Radix could increase the analgesic effect of Aconiti Radix Cocta in mice

with the peak at the rate of 1:1. Conclusion: The combined administration of Ampelopsis Radix and Aconiti Radix Cocta could increase the analgesic effect of Aconiti Radix Cocta

with the peak at the rate of 1:1. This study provides the laboratory basis for further researches on the combined effect between Ampelopsis Radix and Aconiti Radix Cocta.