Fourteen flavonols, four flavones and six isoflavones were isolated from the aerial parts of two Japanese Glycine species, G. tabacina and G. koidzumii, and the leaves of Taiwanese G. max subsp. formosana. Of their flavonoids, twelve flavonols were identified as kaempferol 3-O-sophoroside (1), 3-O-rutinoside (2), 3-O-robinobioside (3) and 3-O-rhamnosyl-(1→4)-[rhamnosyl-(1→6)-galactoside] (4), quercetin 3-O-gentiobioside (5), 3-O-glucoside (6), 3-O-galactoside (7), 3-O-rutinoside (8), 3-O-robinobioside (9) and 3-O-rhamnosyl-(1→4)-[rhamnosyl-(1→6)-galactoside] (10), and isorhamnetin 3-O-rutinoside (11) and 3-O-robinobioside (12). Other two flavonols were characterized as isorhamnetin 3-O-rhamnosylrhamnosylglucoside (13) and 3-O-rhamnosylrhamnosylgalactoside (14). Four flavones and six isoflavones were estimated as schaftoside (15), apigenin 6,8-di-C-arabinoside (16), luteolin 7-O-glucoside (17) and chrysoeriol 7-O-glucoside (18), and daidzein 7-O-glucoside (19), 4'-O-glucoside (20) and 7-O-xylosylglucoside (21), genistein 7-O-glucoside (22) and 4'-O-glucoside (23), and 3'-O-methylorobol 7-O-glucoside (24). Although flavonoid composition of G. tabacina and G. koidzumii was similar to each other, that of G. max subsp. formosana was different with those of two Japanese Glycine species described above. Flavonoids of their Glycine species were reported for the first time except for those of G. tabacina.