A Gram-negative, rod-shaped, non-spore-forming, slightly halophilic bacterium (strain TF-17T) was isolated from an intertidal sediment from the Yellow Sea, Korea. Pigment of strain TF-17T was similar to that of Microbulbifer elongatus, but different from those of Microbulbifer hydrolyticus and Microbulbifer salipaludis. Strain TF-17T was distinguishable from M. elongatus by some phenotypic properties, including motility, optimal growth temperature and others. Phylogenetic analysis based on 16S rDNA sequences showed that strain TF-17TT clustered with the type strains of the three Microbulbifer species with validly published names. Strain TF-17T exhibited 16S rDNA sequence similarity levels of 95.1-95.7% to the type strains of the three Microbulbifer species. The predominant respiratory lipoquinone found in strain TF-17T was ubiquinone-8. The major fatty acid was iso-C(15 : 0) and significant amounts of iso-C(11 : 0) 3-OH and iso-C(17 : 1)omega9c were also present. The DNA G+C content of strain TF-17T was 59.9 mol%. Levels of DNA-DNA relatedness between strain TF-17T and the type strains of the three Microbulbifer species were in the range 10.0-13.0%. On the basis of phenotypic and phylogenetic data and genotypic distinctiveness, strain TF-17T (=KCCM 41774T=JCM 12187T) is proposed as the type strain of a novel species of the genus Microbulbifer, Microbulbifer maritimus sp. nov.