Twenty seven species of pufferfishes (family Tetraodontidae) have been examined to find their generic characters based on olfactory organ, lateral line system, prickles, body form and color characters of specimens collected in 20 places along the coast of Korea from September, 1989 to July, 1994. Based on nostril shape, the genera of Takifugu, Lagocephalus, Plurancanthus, Spheoides and Feroxodon have two nostrils, and those of Ephippion and Canthigaster have a single nostril or nasal tentacle, while Boesernanichthys, Arothron and Chelonodon have no nostril. In the genera of Lagocephalus, Spheoides, Boesemanichthys, Arothron and Feroxodon have only a single well-developed lateral line on the body, in those of Takifugu and Plurancanthus usually have two lateral lines, and those of Chelonodon and Ephippion have two lateral lines merged on the caudal peduncle. Based on the lateral line system and olfactory organ, genus Canthigaster has different characters from the other genera of the family Tetraodontidae. In Ephippion guttifer, the prickles on the dorsal and lateral of the body are enormously enlarged into plates forming a partial carapace. Of the 22 species which have prickly spines, the genera, Lagocephalus, Takifugu stictonotus and Arothron Stellatus have the larger ventral pricklyy spines than the dorsal ones. In genera Lagocephalus most of the species have prickly spines that coverd both the back and belly, while L. inermis has no prickly spines.