A moderately halophilic and alkalitolerant bacterium, designated strain HN30(T), was isolated from garden soil in Japan. Cells of strain HN30(T) were motile, endospore-forming, aerobic, rod-shaped and gram-positive, and contained A1γ meso-diaminopimelic acid-type murein. Growth occurred in 7-23 % (w/v) NaCl (optimum, 10-15 %, w/v), at pH 6.5-10.0 (optimum, pH 8.0-8.5) and at 20-40 °C (optimum, 30 °C). The isoprenoid quinone was menaquinone-7. The polar lipids were phosphatidylglycerol and diphosphatidylglycerol. The major cellular fatty acids were anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(16 : 0) and C(16 : 0). The DNA G+C content of strain HN30(T) was 47 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain HN30(T) was most closely related to Geomicrobium halophilum BH1(T) (93 % sequence similarity). 16S rRNA gene sequence similarities with other recognized species were less than 89 %. Phylogenetic and phenotypic characteristics indicated that strain HN30(T) represents a novel species in a new genus, for which the name Natribacillus halophilus gen. nov., sp. nov. is proposed; the type strain is HN30(T) ( = JCM 15649(T) = DSM 21771(T)).