Among the Chinese drugs, the Ariatolochia species such as A. howfi belong to an important genus of Aristolochiaceae. It is used in the treatment of some bacteria and virus infections in Hainan, but does not inhibit bacterial in vitro Aristolochic acid, the active principle of European species (A. clematitis) possesses phagocyte stimulating action and has been used clinically. In this paper, we separated and purified the acid fraction of Ching-Mu-Xiang (A. debilis) and study its clinical effect, Four crystalline substances have been isolated, Among them two wero identified as aristolochic acid-A (1) and C (2a).The other two compounds are new nitrophenanthrenic acids, and their structures are established as 7-hydroxy aristolochic acid-A (3) and 7-methoxy aristolochic acid-A (4), respectively.