A Gram-stain-negative, non-motile, ellipsoid bacterium, designated HB182678(T), was isolated from brown alga collected from Hainan province, PR China. Growth was observed at 10-50 degrees C (optimum 37-40 degrees C), at pH 6-10 (optimum pH 8) and in the presence of 0.5-13% (w/v) NaCl (optimum, 2-4%). The predominant isoprenoid quinone was Q-10 and the major fatty acids were C-18 : 1 omega 7c, C-16 : 0, C-18 : 0 and C-19 : 0 cyclo omega 8c. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, an unidentified phospholipid, two unidentified glycolipids and three unidentified aminophospholipids. The size of the draft genome was 4.40 Mbp with G+C content 68.8 mol%. Phylogenetic analysis of 16S rRNA gene sequence indicated that strain HB182678(T) belonged to the genus Mangrovicoccus, and the closest phylogenetically related species was Mangrovicoccus ximenensis T1lg56(T) (with the similarity of 96.3%). Whole genome average nucleotide identity (ANI) value between them was 84.3% and in silico DNA-DNA hybridization value was 27.2%. The combined phylogenetic relatedness, phenotypic and genotypic features supported the conclusion that strain HB182678(T) represents a novel species of the genus Mangrovicoccus, for which the name Mangrovicoccus algicola sp. nov. is proposed. The type strain is HB182678(T) (=MCCC 1K04624(T)=KCTC 82318(T)).