The halophilic bacterium Vibrio vulnificus, previously called lactose-positive(L+) Vibrio and Beneckea vulnifica, causes acute, fulminating wound infections and septicemia in humans. Septicemia is very serious infection with a fatality rate of about 50%. Most patients with primary septicemia due to V. vulnificus have preexisting liver disease. V. vulnificus also cause severe wound infections usually after trauma and exposure to marine animals or the marine environment. The mortality rate is not nearly as high as in primary septicemia caused by this organism. In most cases human disease results from ingestion of contaminated seafood or from infection of a wound, frequently of seawater or crab origin. The author made an attempt to isolation of the V vulnificus from seawater, seamud, fish, shellfish, and algae on the southern sea of Korea from January to September in 1987, using for the purpose of vaccine preparation. The author investigated for bacteriological identification, hemolysis and determination of serotypes of isolated V. vulnificus strains. Eighty-five strains(5.9%) out of 1450 specimens collected of V. vulnificus were isolated. The distribution of the 85 isolates were as follows: 21 strains from seawater, 11 strains from seamud, 28 strains from fish, 19 strains from shellfish, and 6 strains from algae, respectively. All 85 isolates were positive reaction on human blood agar. The distribution of serotypes of V. vulnificus isolates were O1 to O8: 13 strains of O1, 6 strains of O2, 11 strains of O3, 9 strains of O4, 10 strains of O5, 7 strains of O6, 15 strains of O7, and 10 strains of O8, respectively. Eighty-one strains showed agglutination with O antisera, but 4 strains failed to show agglutination. In this study, the author suspected that serotypes of V. vulnificus isolates distributed also in the seaside of Korea as well as in most seaside of the world, and new serotypes were in existence in the seaside of Korea except reported up to now.