A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterium, designated 15J8-9(T), was isolated from a sandy beach in Jeju Island, South Korea. The isolate was able to grow between 10 and 30 A degrees C, pH 5-8, and in presence of 0-1% (w/v) NaCl. Based on 16S rRNA gene phylogenetic analysis, the novel strain was closely related to members of the genus Spirosoma (96.1-90.9% similarities) and showed highest sequence similarity to Spirosoma panaciterrae DSM 21099(T) (96.1%). The G + C content of the genomic DNA of strain 15J8-9(T) was 45.1 mol%. The isolate contained menaquinone MK-7 as the predominant respiratory quinone, phosphatidylethanolamine as the major polar lipid, and summed feature 3 (C-16:1 omega 6c/C-16:1 omega 7c; 28.0%), C-16:1 omega 5c (23.4%), iso-C-15:0 (13.5%), and C-16:0 (11.5%) as the major fatty acids that supported the affiliation of strain 15J8-9(T) to the genus Spirosoma. The isolate could be differentiated clearly from recognized Spirosoma species on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore, strain 15J8-9(T) is considered to represent a novel species of the genus the genus Spirosoma, for which the name Spirosoma harenae sp. nov. is proposed. The type strain is 15J8-9(T) (= KCTC 52030(T) = JCM 31993(T)).