A novel non-sporulating, non-motile, catalase-positive, oxidase-negative, facultatively anaerobic, Gram-positive coccus, designated strain JSM 078151(T), was isolated from an intertidal sediment sample collected from Naozhou Island in the South China Sea, China. Growth was found to occur in the presence of 0-15 % (w/v) NaCl (optimum 0.5-3 % (w/v) NaCl), at pH 6.5-10.5 (optimum pH 7.0-8.0) and at 5-35 °C (optimum 25-30 °C). The peptidoglycan type was determined to be A3a, containing lysine, glutamic acid and alanine. The major cellular fatty acid identified was anteiso-C15:0 and the predominant menaquinones are MK-7 and MK-8. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylglycerol, glycolipid and one unidentified phospholipid. The genomic DNA G+C content of strain JSM 078151(T) was determined to be 55.2 mol%. A phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain JSM 078151(T) should be assigned to the genus Rothia, and was most closely related to Rothia nasimurium CCUG 35957(T) (98.3 % sequence similarity), followed by Rothia amarae J18(T) (97.5 %) and Rothia terrae L-143(T) (97.3 %). A combination of phylogenetic analysis, DNA-DNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the suggestion that strain JSM 078151(T) represents a novel species of the genus Rothia, for which the name Rothia marina sp. nov. is proposed. The type strain is JSM 078151(T) (= DSM 21080(T) = KCTC 19432(T)).