A Gram-positive, slightly halophilic, rod-shaped bacterium, designated CL-DD14(T), was isolated from seawater of the East Sea, Korea. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain CL-DD14(T) belongs to the genus Nocardioides. Levels of 16S rRNA gene sequence similarity between strain CL-DD14(T) and the type strains of recognized species of the genus Nocardioides were low (94.1-97.1 %). Strain CL-DD14 (T) grew over the pH range 6-9 and temperature range 10-40 degrees C. The strain grew at NaCl concentrations of 0.5-8 % (w/v) with optimum growth at 1-3 % and no growth was observed after 3 weeks on nutrient agar without any salts. It contained ll-diaminopimelic acid as the diamino acid in the cell wall. The major isoprenoid quinone was MK-8(H(4)) and the major cellular fatty acids were iso-C(16 : 0) and 10-methyl C(17 : 0). The DNA G+C content was 72.9 mol%. On the basis of phenotypic and phylogenetic data, strain CL-DD14(T) is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides marinus sp. nov. is proposed. The type strain is CL-DD14(T) (=KCCM 42321(T)=DSM 18248(T)).