The molecular structures of 3 isoflavone glycosides isolated from the root wood of Erythrina latissima were established as 4'-hydroxyisoflavone-7-O-beta-D-glucopyranoside (compound 1); 4'-hydroxyisoflavone-7-O-alpha-L-rhamnosyl (1-->6)-beta-D-glucopyranoside (compound 2); and a new compound 4', 8-dimethoxy isoflavone-7-O-alpha-L-rhamnosyl (1-->6) glucopyranoside (8-O-methylretusin-7-O-alpha-L-rhamnosyl (1-6)-beta-D-glucopyranoside) (compound 3).