A new triterpenoid saponin was isolated from Pulsatilla cernua, along with eight known triterpenoids and triterpenoid glycosides. The new compound was identified as 3-O-beta-D-glucopyranosyl-(1-->4)-alpha-L-arabinopyranosyl-bayogenin-28-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (1) on the basis of 1D, 2D-NMR techniques, including COSY, HMBC, and HMQC correlations, MS analysis, as well as chemical methods.