An aerobic, rod-shaped, Gram-positive, oxidase-positive, catalase-positive bacterial isolate, strain YLB-01T, was characterized using phenotypic and molecular taxonomic methods. The 16S rRNA gene sequence analysis revealed that the isolate belonged to the genus Microbacterium and represented an evolutionary lineage that was distinct from recognized Microbacterium species. Cell-wall hydrolysate from the isolate contained the amino acids ornithine, alanine, glycine homoserine (Hsr) and glutamic acid, and the cell-wall sugars consisted of ribose, glucose and galactose. The main respiratory quinones were MK-8, 9, 10. The major cellular fatty acids were anteiso-Ci5:0 (38.5 ％), anteiso-CI7:o(23.1 ％) and Ci6:o (18.9 ％). The DNA G+C content was 71 mol％. The isolate showed <98 ％ 16S rRNA gene sequence similarity with respect to all of the Microbacterium species with validly published names. On the basis of the morphological, physiological and chemotaxonomic data and the results of the comparative 16S rRNA gene sequence analysis, this isolate represents a novel species of the genus Microbacterium, for which the name Microbacterium sediminis sp. Nov. Is proposed. The type strain is YLB-01T (=DSM23767T=CCTCC AB20103637 =MCCC 1AO6153T).