The root of Pulsatilla cernua SPRENG. (Japanese name: 'Hakutoo') has been used as a home remedy for antitumor, astringent, antilaxative, diuretic and so on, but the original plants of commercial 'Hakutoo' are different in each market. We have investigated the saponin constituents of Pulsatilla species in various habitats. Four triterpenoid saponins (I-IV), isolated from the root of Pulsatilla cernua, were characterized as follows: I, hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside; II, 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside; III, 3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosyl-hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside; IV, hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranoside. III and IV are new saponins. II and III were also detected in Pulsatilla koreana and P. chinensis on TLC.