A new triterpenoid glycoside,3-β-O-β-D-glucopyranosyl presenegenin 28-O-α-L-arabipyranosyl(1→3)-β-D- xylopyranosyl(1→4)-[β-D-apiofuranosyl(1→3)]-α-L-rhamnopyranosyl(1→2)-[α-L-rhamnopyranosyl(1→3)]-β-D-fucopyra- nosyl ester (1)was isolated from the Polygala tenuifolia Willd.,together with two known sapordns,including polygalasapo- ninⅩⅩⅣ(2)and polygalasaponinⅩⅩⅧ(3).The structure of new compound was elucidated by spectroscopic methods. A new triterpenoid glycoside, 3-β-O-β-D-glucopyranosyl presenegenin 28-O-α-L-arabipyranosyl (1 → 3) -β-D-xylopyranosyl (1 → 2) - [α-L-rhamnopyranosyl (1 → 3)] - β-D-fucopyra-nosyl ester (1) was isolated from the Polygala tenuifolia Willd. together with two known sapordns, including polygalasapo- nin XXX (2) and polygalasaponin XXVIII (3). The structure of new compound was elucidated by spectroscopic methods.