A Gram-stain-negative, strictly aerobic and rod- to coccoid-shaped bacterium, designated as strain M366 T , was isolated from coastal sediment of Jiaoshanjiao, Zhejiang Province, PR China (121°54' E 29 °38' N). The draft genome of strain M366 T was 3 225 479 bp long (with 55.6 mol% G+C content) and assembled into four contigs. The N50 value was 563 270 bp and the genomic completeness and contamination were estimated to be 99.34 and 0.05 %, respectively. Colonies of strain M366 T were yellow-orange, 1 mm in diameter, round, opaque, smooth and convex after incubation on marine agar at 30 °C for 3 days. Cells were catalase-positive but oxidase-negative. Strain M366 T was observed to grow at 20-40 °C (optimum, 30 °C), pH 5.5-9.0 (optimum, pH 6.5-7.0) and with 0.5-8.0 % (w/v) NaCl (optimum, 2.5 %). Strain M366 T shown highest 16S rRNA gene sequence similarity of 98.1 % to Robiginitalea sediminis O458 T , 95.6-95.9 % to other type strains of the genus Robiginitalea and below 93 % to other genera. The average nucleotide identity and digital DNA-DNA hybridization values between strain M366 T and its closely related Robiginitalea species were 71.1-75.9 % and 17.5-19.0 %. Menaquinone-6 was the only respiratory quinone. The major fatty acids (>10 %) were iso-C 15 : 0 , iso-C 17 : 0 3-OH and summed feature 1 (iso-C 15 : 1 h and/or C 13 : 0 3-OH). The main polar lipids included phosphatidylethanolamine, two unidentified phospholipid, two unidentified aminophospholipid, one unidentified glycolipid and five unidentified lipids. According to the above results, Robiginitalea aestuariiviva sp. nov. is proposed and the type strain is M366 T (=KCTC 92866 T =MCCC 1K04524 T =CGMCC 1.61708 T ).