Three strains of Gram-negative, aerobic, neutrophilic and halophilic bacteria were isolated from samples of a salt lake on the Qinghai-Tibet Plateau and a subterranean saline well in the Si-Chuan Basin of China. These isolates, designated AJ275(T), AJ282(T) and ZG16(T), were investigated using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the isolates could be affiliated to the genus Halomonas. Genomic DNA G+C contents were 65.9 mol% for AJ275(T), 56.7 mol% for AJ282(T) and 57.6 mol% for ZG16(T). The results of DNA-DNA hybridizations, fatty acid analysis and physiological and biochemical tests allowed the isolates to be differentiated genotypically and phenotypically from closely related species. It is proposed that strains AJ275(T) (=CGMCC 1.6493(T)=JCM 14606(T)=LMG 23976(T)), AJ282(T) (=CGMCC 1.6494(T)=JCM 14607(T)=LMG 23978(T)) and ZG16(T) (=CGMCC 1.6495(T)=JCM 14608(T)=LMG 23977(T)) represent the type strains of three novel species in the genus Halomonas: Halomonas saccharevitans sp. nov., Halomonas arcis sp. nov. and Halomonas subterranea sp. nov., respectively.