A bacterial strain, labeled UR11T, was isolated from green alga Ulva pertusa collected from Jeju Island, Korea. UR11T was identified as a gram-negative, rod-shaped, motile by gliding and aerobic bacterial strain with yellow colonies on R2A plates. The strain UR11T grew over at a temperature range of 10°C to 30°C (optimally at 25°C), a pH range of 6.0-11 (optimally at pH 7.0) and a Nacl range of 0.5-5% Nacl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain UR11T was a member of the genus Flavobacterium. Strain UR11T shared close similarity with F. jejuensis EC11T (98.0%) F. jumunjinense HME7102T (96.1%), F. haoranii LQY-7T (95.3%), F. dongtanense LW30T (95.1%), and F. ahnfeltiae 10Alg 130T (94.9%). The major fatty acids (>5%) were iso-C15:0 (33.9%), iso-C15:1 G (12.4%), iso-C17:0 3-OH (9.0%), iso- C16:0 (7.0%) and iso-C15:0 3-OH (6.3%). The major polar lipids were phosphatidylethanolamine, seven unknown aminolipids, two unknown aminopolarlipids and two unknown lipids. DNADNA hybridization value was 58% at strain UR11T with F. jejuensis EC11T . Based on phenotypic, chemotaxonomic and phylogenetic evidence, strain UR11T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium jocheonensis sp. nov. is proposed. The type strain is Flavobacterium jocheonensis is UR11T (=KCTC 52377T =JCM 31512T.