Araliaceous species containing ginsenosides, the major active component in Panax species, were surveyed using ELISA and eastern blotting with anti-ginsenoside Rb1 monoclonal antibody. Immunoassay-guided fractionation of the methanol-soluble extracts of Araliaceous species led to the isolation of a known compound in the bark of Kalopanax pictus Nakai. The known compound was identified as ginsenoside Rb1 by spectroscopic methods and by comparison with an authentic sample. The result provided evidence that a combination of two immunoassays using monoclonal antibodies against ginsenosides is a powerful means of surveying new ginsenoside resources.