Objective: To analyze the rationality of Eryan Huguo decoction(EYHGD). Method: Ammonia water stronger nebulization was used to analyze the effects of preventing cough

and mouse's auricle swelling induced by xylene were used to analyze the effects of antiinflammatory. The indexes of pharmacodynamics were used to screen the suitable extraction solvent. Its dismantle compatibility was studied by removing one kind of herbal medicine of the complex prescription. Result: The suitable solvent was 55% ethyl alcohol. Each kind of herbal medicine in the prescription had some effects

the sequence of which was as follows:Lysionotus pauciflorus >Bergenia scopulosa >Bulbophyllum odoratissimum >Polygonum cuspidatum. Conclusion: The prescription formula of EYHGD is reasonable. Its compatibility relation is as follows:L. pauciflorus is principal drug

B. scopulosa is ministerial drug

B. odoratissimum is adjunctive drug and P. cuspidatum is messenger drug

which was similar to the primitive prescription.