This study was carried out to investigate the distribution of V. parahaemolyticus in Incheon adjacent sea, and anti-microbial effect on growth of V. parahaemolyticus in organic acid. The detected strains were compared for geography, months and sample types. V. parahaemolyticus was detected form 28.5 percent of 287 samples collected from Incheon area, and 34.7 percent of 91 samples collected in the months of July through September, and 24.7 percent of 279 shellfish samples respectively. The minimun inhibitory concentration(MIC) of organic acid in V. parahaemolyticus were 1,250ppm at propionic acid, citric acid and acetic acid, 2,500ppm at vanillic acid, respectively. MICs of combined treatment of acetic acid and vanillic acid, citric acid and vanillic acid, propionic acid and vanillic acid were 1,250 ppm. MICs of combined treatment of citric acid and acetic acid, propionic acid and acetic acid, propionic acid and citric acid was 12.5ppm. The antimicrobial effect of organic acid in V. parahaemolyticus was confirmed from the result of this experiment.