Seven triterpenoidal saponins, onjisaponins A, B, C, D, E, F, and G, were isolated from the roots of Polygala tenuifolia WILLDENOW. Among these saponins, the structures of onjisaponins G (1) and F (2) were determined on the basis of spectral and chemical evidence as presenegenin-(3)-β-D-glucopyranosido-(28)-2-O-{[β-D-apio-D-furanosyl (1→3)]-[β-D-xylopyranosyl (1→4)]-α-L-rhamnopyranosyl}-4-O-(3', 4', 5'-trimethoxycinnamoyl)-β-D-fucopyranoside and presenegenin-(3)-β-D-glucopyranosido-(28)-2-O-{[β-D-apio-D-furanosyl-(1→3)] [α-L-arabinopyranosyl (1→3)-β-D-xylopyranosyl (1→4)]-α-L-rhamnopyranosyl}-4-O-(3', 4', 5'-trimethoxycinnamoyl)-β-D-fucopyranoside, respectively.