A Gram-positive, non-spore-forming isolate, designated YIM 70212(T), was isolated from a hypersaline soil sample collected from Qinghai, north-west China. Cells of the isolate were orange-pigmented, motile cocci with multiple flagella. A polyphasic taxonomic investigation was carried out on the isolate. The organism grew at 10-45 degrees C and pH 7.5-11.0, with optimum growth at 28 degrees C and pH 8.0-9.5. Strain YIM 70212(T) grew optimally in the presence of 10 % NaCl, KCl or MgCl(2).6H(2)O and growth was observed in 1-25 % NaCl, KCl or MgCl(2).6H(2)O. The peptidoglycan type was A1gamma. Ribose and minor amounts of galactose were detected as the whole-cell sugars. MK-5 was the only menaquinone. The major cellular fatty acids were ai-C(15 : 0) (52.4 %) and ai-C(17 : 0) (26.5 %). The DNA G+C content was 47.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM 70212(T) formed a distinct lineage within the order Bacillales and was most closely related to members of the genus Marinococcus, showing 16S rRNA gene sequence similarity levels of 91.0-91.4 %. Based on the high 16S rRNA gene sequence divergence and differences in phenotypic characteristics, it is proposed that the unknown strain be classified in a novel genus and species with the name Sinococcus qinghaiensis gen. nov., sp. nov.; the type strain of Sinococcus qinghaiensis is YIM 70212(T) (=KCTC 3943(T)=DSM 17008(T)).