Abstract: Isodon amethystoides (Benth) C Y Wu et Hsuan is an effective drug used for the treatment of inflammation. Ten components were isolated from the ethanolic extract of the plant with the aid of column chromatography. Four of these components have been identified as palmitic acid (Ⅱ), umbrosin A (Ⅸ), umbrosin B (Ⅵ) and 14-acetyl-umbrosin B(Ⅳ). The last one is a new ent-kaurenoid diterpene isolated from the genus of Isodon. Studies of the chemical structure of the other six components are in progress.