Bioassay-guided fractionation of and root extracts afforded six compounds. Among these, two bioactive compounds ginsenoside Re () and (20)-ginsenoside Rg2 () exhibiting significant relaxation in rabbit corpus cavernosum with EC values of 95.1 and 114.7 μM, respectively. In addition, the phytochemical composition of the water extract of the roots of was investigated, and thirty-one compounds were characterized, including four undescribed compounds panajaponol B () and panaxjapynes D-F (-). Moreover, the spectral characteristics and biosynthetic pathway of triterpene saponins were discussed according to our results and some previous reports.