In the eastern blotting method, a new fashion to separate the ginsenoside molecule into two functional parts using a simple and well-known chemical reaction was developed. In principle, the sugar moieties were oxidized by NaIO4 to form dialdehydes, which reacted with amino groups of the protein and covalently bound to the adsorbent PVDF membrane. The MAb bound to the aglycon part of the ginsenoside molecule for immunostaining. Double staining of eastern blotting for ginsenosides using anti-ginsenoside -Rb1 and –Rg1 MAbs promoted complete identification of ginsenosides in Panax species. As an application, we analyzed several Araliaceous plants by eastern blotting and enzyme-linked immunosorbent assay (ELISA) using anti-ginsenoside Rb1 MAb leading to the investigation of ginsenoside Rb1 from Kalopanax pictus and Acanthopanax koreanum. On the other hand, by immunoassay-guided fractionation and chromatography separation on the methanol extract of American ginseng, two new minor ginsenosides were isolated. As another application, identification of two known ginsenosides was achieved from the P. japonicas extract using eastern blotting and immunoaffinity column combined with anti-ginsenoside Rb1 MAb.