Almost all Panax spp. (family Araliaceae) have been used in folk medicine. The most famous variety is P. ginseng, which was recorded in Chinese Materia Medica 2000 years ago. It is used to enhance stamina and capacity to cope with fatigue and physical stress, and in tonics against cancers, disturbances of the central nervous system (memory, learning, and behavior), hypothermia, carbohydrate and lipid metabolism, immune function, the cardiovascular system and radioprotection. Meanwhile, P. notoginseng, cultivated extensively in Kumming province in China, is also an important crude drug used as an astringent and tonic. P. japonicus grows mainly in Japan and China and is used as a stomachic and a hairgrowth tonic in Japan. In ginseng markets worldwide, P. quinquefolius usually commands a much higher price than P. ginseng. Since the roots of these ginseng products are similar in appearance and many commercial ginseng products are in the form of a powder or shredded slices, identification of the origins of ginseng products is not an easy task. Authentication of the sources of ginseng and ginseng products based on scientifically profiling has aroused much interest. Ginsenosides (ginseng saponins) are known to be bioactive components of ginseng. According to the difference in aglycon in these saponins, ginsenosides are classified into three types: the 20(S)-protopanaxadiol type [e.g., ginsenosides Rb1 (G-Rb1), -Rc (G-Rc), -Rb2 (G-Rb2), -Rd (G-Rd); malonylginsenosides Rb1 (MG-Rb1), -Rb2 (MG-Rb2) and -Rc (MG-Rc)], the 20(S)-protopanaxatriol type [e.g., ginsenosides Rg1 (G-Rg1), -Rf (G-Rf), and -Re (G-Re)], and the oleanolic acid type [e.g., ginsenoside Ro (G-Ro)] (see Figure 1). Ginsenosides have been shown to affect various biological processes: e.g., tumor metastasis and anti-diabetes effects (Wu et al., 1992; Newman et al., 1992), the central nervous system (Kim et al., 1990; Kim et al.,1996; Tokuyama et al., 1996;), and retardation of the aging process (Metori et al., 1997). It is well known that the content of ginsenosides varies in ginseng root or root extract depends on the method of extraction, subsequent treatment, or even the season of collection (Kim et al., 1981); therefore, standardization of quality is essential. Many analytical approaches have been used to identify ginsenosides in ginseng extract (Sticher and Soldati, 1979; Soldati and Sticher, 1980; Tani et al., 1981; Kitagawa et al., 1987; Yamaguchi et al., 1988; Samukawa et al., 1995; Wang et al., 1999; Chan et al., 2000; Li et al., 2000). We have prepared monoclonal antibodies (MAbs) against major active compounds of P. ginseng, G-Rb1 (Tanaka et al., 1999) and G-Rg1 (Fukuda et al., 2000a), and established an