OBJECTIVE：To study the effects of the compatibility of medicinal materials on the content of icariin in Gushuling granules formula. METHODS：The effects of the compatibility of medicinal materials on the content of icariin was investigated by orthogonal design with the compatibility of Astragalus membranaceus，Achyranthes bidentata and Concha ostreae as factors，using the content of icariin in decoction as index. The pH of mixture of Epimedium brevicornu and A. membranaceus，and the content of icariin in precipitation were determined. RESULTS：The effects of the compatibility of A. membranaceus on the content of icariin had statistical significance（P＜0.05）；the compatibility of A. bidentata and C. ostreae had no statistical significance（P＞0.05）； the interactions between two medicinal materials had not been found；the pH of the mixtures had no significant difference；the compatibility of E. brevicornu and A. membranaceus produced precipitation，and the content of icariin in precipitation increased. CONCLUSIONS： The compatibility of E. brevicornu and A. membranaceus can produce precipitation，so as to decrease the content of icariin in decoction，which is not influenced by pH value of decoction.