Two Gram-positive, endospore-forming, rod-shaped bacterial strains, HG645(T) and HG711, were respectively isolated from surface water of a brackish lake and sediment of a fishery harbour in Japan and were subsequently characterized taxonomically using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains HG645(T) and HG711 are affiliated phylogenetically to the genus Sporosarcina, and they exhibit sequence similarities of 95.7-97.3 % to the type strains of Sporosarcina species. DNA-DNA relatedness between strain HG645(T) and the type strain of the phylogenetically related species Sporosarcina aquimarina was less than 10 %. The DNA G+C content of strains HG645(T) and HG711 were respectively 46.0 and 45.2 mol%. Major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The cell-wall peptidoglycan type (Lys-Glu), major cellular fatty acids (iso-C(15 : 0) and anteiso-C(15 : 0)) and quinone type (MK-7) of the isolates support their affiliation to the genus Sporosarcina. On the basis of phylogenetic analysis and physiological and chemotaxonomic data, the isolates represent a novel species of the genus Sporosarcina, for which the name Sporosarcina saromensis sp. nov. is proposed. The type strain is strain HG645(T) (=MBIC08270(T)=IAM 15429(T) =KCTC 13119(T)).