Eight species of Sargassum subgenus Bactrophycus section Halochloa and Repentia were collected from the coasts of Korea: Sargassum coreanum J. Agardh, Sargassum sagamianum Yendo, Sargassum micracanthum (K?tzing) Endlicher, Sargassum macrocarpum C. Agardh, Sargassum autumnale Yoshida, Sargassum siliquastrum (Mertens ex Turner) C. Agardh, Sargassum serratifolium (C. Agardh) C. Agardh, Sargassum yezoense (Yamada) Yoshida et Konno. These species were investigated on morphological variations and geographical distributions in Korea. The valuable taxonomic characters between similar species of these section were discussed with special reference to types of holdfasts, shape of main branch, leaves and vesicles.