Abstract:The results of experimental studies on the cornpatible using of Fructus Evodiae with Rhizoma Coptidis showthat in the decoction of the two drugs there is an additive property for the chemical constituents and no new chemi-cal substances were found. But the decocting rate of berberine,the main constituent of Rhizoma Coptidis,decreasesbv 37.0%after decocting with Fructus Evodiae.