Two Gram-positive, motile, rod-shaped, halophilic bacteria showing optimum growth at 5-7 % (w/v) NaCl were isolated from a salt lake, Xin-Jiang Province, China. The strains, designated BH312(T) and BH314, grew in the presence of 1-18 % (w/v) NaCl and at temperatures of 15-50 degrees C (optimum: 40 degrees C) and pH values of 5.5-10.0 (optimum: pH 7.5-8.0). The major cellular fatty acids were anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0). The DNA G+C content was 38.8-39.0 mol% and the predominant lipoquinone was MK-7. The major cellular phospholipids were phosphatidylglycerol, diphosphatidylglycerol and two unidentified phospholipids. Phylogenetic analyses based on 16S rRNA gene sequences showed that the isolates formed a cluster with Gracilibacillus orientalis XH-63(T) within the genus Gracilibacillus. The levels of 16S rRNA gene sequence similarity with closely related type strains were lower than 96.2 %. On the basis of phylogenetic, phenotypic and chemotaxonomic properties, the isolates represent a novel species of the genus Gracilibacillus for which the name Gracilibacillus lacisalsi sp. nov. is proposed. The type strain is BH312(T) (=KCTC 13129(T)=DSM 19029(T)).