Microbacterium strains JS53-2T and JS53-5 were isolated from sea water in the South Sea of Korea and subjected to phenotypic, chemotaxonomic and genetic characterization. The cells were found to be Gram-positive. These strains contained MK-11 and MK-12 as the main respiratory quinones and anteiso-C15:0, anteiso-C17:0 and iso-C16:0 as the major cellular fatty acids. The DNA G+C content was 68 mol%. The cell-wall sugars of the isolates were galactose and xylose, and the diamino acid in the cell-wall hydrolysates was lysine. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolates represented an evolutionary lineage distinct from those of other Microbacterium species. DNA-DNA reassociation values between the isolates and reference strains Microbacterium terregens KCTC 19034T, Microbacterium lacticum KCTC 9230T, Microbacterium aurum KCTC 19091T and Microbacterium schleiferi KCTC 19095T were below 23%. On the basis of evaluation of the morphological, physiological and chemotaxonomic characteristics, 16S rRNA gene sequence comparisons and DNA-DNA hybridizations, a novel species, Microbacterium koreense sp. nov., is proposed for these isolates. The type strain is JS53-2T (=KCTC 19074T=CIP 108696T=CCUG 50754T).