Two new cycloartane glycosides, thalictosides A (1) and C (2), were isolated from the aerial part of Thalictrum thunbergii D.C. They were constituted of a new triterpenoidal sapogenol named thalictogenin a, that is, 3β, 22S, 26-trihydroxycycloartan-24-ene. Their structures were characterized as 3-O-β-D-quinovopyranosyl (1→6)-β-D-glucopyranosyl-(1→4)-β-D-fucopyranosyl thalictogenin a (1) and 3-O-β-D-glucopyranosyl-(1→6)-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-fucopyranosyl thalictogenin a (2) on the bases of the chemical evidence and spectroscopic means.