Abstract: Commercial samples of the drug Yuan Hua obtained from 39 Chinese cities and towns have been examined and found that all these samples are the flowers of either Daphne genkwa Sieb.et Zucc.or Wikstroemia chamaedaphne Meisn.,both belong to the family Thymelaeacese. After careful examination and comparison of the descriptions and illustrations of Yuan Hua in ancient Chinese herbals,the author ascertained that the flower of Daphne genka is the Yuan Hun described in Wus Pen Tsao,Ming Yi Bie Lu and Shu Pen Tsdo,it is also the Tsuchow Yuang Hua recorded in Tzeng Lei Pen Tsao;while the flower of Wikstroemia chamaedaphne is the Huang Yuan Hua of Tu Jing Pen Tsao and the Jiangchow Yuan Hua of Tzeng Lei Pen Tsao.This latter species was mistakenly iden- tified as Wikstroemia trichotoma Mak.by Nakao. The morphology,histology as well as the plant habit of the drug Yuan Hua and Huang Yuan Hun are examined and described in detail with twelve illustrations.