Basic fibroblast growth factor (bFGF)-like immunoreactivity was detected in extracts of Panax ginseng root by using a sensitive two-site enzyme immunoassay specific for human bFGF (hbFGF). In an investigation of the molecular properties of this bFGF-like molecule (bFGF-LI), the bFGF-LI and hbFGF were found to be equivalent with respect to antigenicity, molecular weight, isoelectric point, affinity for binding to heparin, and mitogenic activity toward BALB/c3T3 fibroblasts. The identification of this bFGF-LI molecule in Panax ginseng root helps to explain various activities of the traditional Chinese medicine ginseng.