A Gram-negative, aerobic, motile by flagellum, and rod-shaped bacterium, designated ASW11-7( T), was isolated from coastal surface seawater sample collected from the Yellow Sea, PR China. Strain ASW11-7( T )grew optimally at 37?, 4.0%(w/v) NaCl and pH 7.0. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain ASW11-7( T )belongs to the genus Alteromonas and most closely related to Alteromonas ponticola MYP5 T (99.6% similarity), followed by Alteromonas confluentis DSSK2-12 T (98.2%), Alteromonas lipolytica JW12( T) (98.2%), and Alteromonas hispanica F-32( T) (98.0%). The draft genome of strain ASW11-7( T) had a length of 3,530,922 bp with a G+ C content of 44.9%, predicting 3108 coding sequences, 5 rRNA, 4 ncRNAs, 49 tRNAs genes, and 18 pseudogenes. The average nucleotide identity and digital DNA-DNA hybridization values between genomic sequences of strain ASW11-7( T) and closely related species of Alteromonas were in ranges of 66.9-77.8% and 18.3-27.5%, respectively. The major fatty acids of strain ASW11-7( T) were C 16: 0, summed feature 3 (C-16:1 ?7c/C-16:1 ?6c), and summed feature 8 (C-18:1 ?7c/C (18:1) ?6c). The predominant respiratory quinone was Q-8 and the major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. Based on the phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain ASW11-7( T) is considered to represent a novel Alteromonas species, for which the name Alteromonas aquimaris sp. nov. is proposed. The type strain is ASW11-7( T) (= KCTC 92853( T)= MCCC 1K07240( T)).