A seriea of new aglycones has been isolated from Picriczfel-tarrae Lour. Picfeltarraogenin I(1) which is the major aglyoone of this plant, has a molecular formula of C₃₀H₄₄0₅ m. p. 209-210℃, [α] ¹⁸_D+158.9°(c. 1.00, MeOH).The structure of 1 which was determined by means of spectral analysis(UV, IR, 1HNMR, ¹³C NMR and MS) and chemical reactions, was proves to be a new tetracyelie triterpenoid with a characteristic side chain of 3-2H]-furanone. Piofeltarraenins, the glycosides of piofeltarraegenins, were shown to possess significant antitumor activity.