Typing and identification of 60 marine psychrophilic and psychrotrophic vibrios isolated from the north-western Pacific Ocean and coastal environment of Japan were performed by restriction fragment length polymorphism analysis on the basis of polymerase chain reaction amplified 16S rDNA. We obtained 15 operational taxonomic units (OTUs) by digestion with four restriction endonucleases (HhaI,DdeI,RsaI, andSau3AI); four large groups were obtained from the neighbor-joining method. Significant differences were observed in OTU composition between isolates from the deep sea and coastal areas.Vibrio marinusandPhotobacteriumspecies were the dominant culturable vibrios in the deep sea areas, whileVibriosplendiduslike species were the dominant culturable vibrios in a coastal area of Japan.Key words: restriction analysis,Vibrio,Photobacterium, Vibrio marinus(Moritella marina),Vibrio splendidus.