Two new triterpenoid saponins, wistariasaponins D [1] amd G [2], and the known saponin dehydrosoyasaponin I [3] were isolated from the knots of Wistaria brachybotrys. The Structures of 1 and 2 were determined from their chemical and physicochemical evidence. The inhibitory effects of these saponins on the activation of Epstein-Barr virus early antigen that was induced by a tumor promoter were also tested for the primary screening of antitumor-promoting activities.