Cyrtominetin and cyrtopterinetin, isolated from Cyrtomium falcatum Presl. and other Cyrtomium species as flavonoid aglycones, were proved to be 6, 8-dimethyl-5, 7, -3', 4'-tetrahydroxyflavanone and 6, 8-dimethyl-5, 7, 4'-trihydroxyflavanone, respectively, by their methylation and alkali fusion. Their syntheses were achieved by Shinoda's method and the products proved to be identical with racemic cyrtominetin and cyrtopterinetin.