The Baiqian (白前) and the Baiwei (白薇) are widely used as herbal medicine in Asian countries. They possess different pharmacological effects in the clinical therapy. The adulteration and misusage of each has been reported in the literature. In this study, we purchased samples of both from fifty sellers of Chinese natural drugs in Taipei area, and identified their origins by morphology, microscopy and thin layer chromatography methods with their authenticated materials. The results showed that the identification of fifty samples of the Baiqian as the Cynanchum atratum Bunge. (直立白薇) and the Cynanchum glaucescens (Dec.) Hand.-Mazz (芫花葉白前) were forty seven and three, respectively. On the contrary, the identification of fifty samples of the Baiwei as the Cynanchum glaucescens (Dec.) Hand.-Mazz., the Cynanchum stauntoni (Decne.) Schltr.ex Levl. (柳葉白前) and the Cynanchum atratum Bunge. were forty six, two and two, respectively. Furthermore, none of the sellers of Chinese natural drugs sold the correct origins of the products. Selling samples of both with no difference as the Cynanchum glaucescens and the Cynanchum atratum was found in three and two herbal stores, respectively. Misusage of each was present in the other stores. The adulteration and misusage between the Baiqian and the Baiwei in marketing were found to be very serious in this study.