Poria cocos is one of the commonly used traditional Chinese medicines (TCM) which is the principal ingredients of the Ling-Gui-Zhu-Gan decoction. 26 samples of Poria of different origins were collected and the quality assessment was developed. Dehydrotumulosic acid, one of the triterpenes was isolated and identified. Pure dehydrotumulosic acid for quantification was prepared. A reversed-phase HPLC method has been developed for the determination of dehydrotumulosic acid in Poria cocos. The determi...