Abstract: AimTo isolate triterpene saponins of polygalacic acid type from the roots of Platycodon grandiflorum (Jacq.) A.DC and to identify their structures. MethodsThe compounds were separated by means of extraction, chromatography on silica gel, MPLC and HPLC, and their structures were elucidated on the basis of spectral analyses (FAB-MS, IR, ¹H NMR, ¹³C NMR etc.). ResultsThree triterpene saponins were isolated from the roots of Platycodon grandiflorum. They were identified as 3-O-β-D-laminaribiosyl polygalacic acid (I), 3-O-β-D-glucopyranosyl polygalacic acid (II), polygalacin D (III), separately. ConclusionCompound I is a new compound, compounds II, III are known triterpene saponins. The compound I and II were isolated from the plant for the first time, which is also the monodesmoside from the plant for the first time.