A Gram-stain-negative, aerobic bacterial strain, designated strain m18T, was isolated from a sea-tidal flat in South Korea. Cells were non-motile short rods showing oxidase and catalase activities. Growth of m18T was observed at 10-40 °C (optimum, 30 °C), pH 5.5-10.0 (optimum, pH 7.0) and 0.5-7.0 % (w/v) NaCl (optimum, 3.0 %). The major respiratory quinone was ubiquinone-10 and the major fatty acids of were summed feature 8 (comprising C18 : 1ω7c/C18 : 1ω6c) and C16 : 0. The G+C content of the genomic DNA was 56.7 mol%. Phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, an unidentified phospholipid, an unidentified aminolipid and four unidentified lipids were detected in m18T. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that m18T formed a tight phyletic lineage with the members of the genus Amylibacter. Strain m18T was most closely related to Amylibactercionae H-12T, Amylibacter ulvae 6Alg 255T and Amylibacter marinus 2-3T with 98.9, 96.1 and 95.5 % 16S rRNA gene sequence similarities, respectively. The DNA-DNA hybridization value between m18T and the type strain of A. cionae was 43.6±3.4 %. On the basis of phenotypic, chemotaxonomic and molecular properties, m18T represents a novel species of the genus Amylibacter, for which the name Amylibacterlutimaris sp. nov. is proposed. The type strain is m18T (KACC 19229T=JCM 32051T).