A bacterial strain, designated $Iso4^T$, was isolated from the East Sea of Korea and was subjected to a poly-phasic taxonomy study including phenotypic and chemotaxonomic characteristics as well as 16S rRNA gene sequence analysis. Cells of the strain were Gram-negative, motile, non-budding, non-stalked, and strictly aerobic. Strain $Iso4^T$ grew optimally at $20^{circ}C$ in the presence of 1~2% (w/v) NaCI and at pH 6.9~7.6. The major respiratory quinone was Q-10 and the major cellular fatty acids were $C_{18:1}$ ${omega}7c$ (53.5%), $C_{17:1}$ ${omega}5c$ (11.7%), $C_{17:1}$ ${omega}6c$ (8.1 %), $C_{16:0}$ (7.8%), $C_{17:0}$ (4.8%), $C_{15:0}$ (2.9%), and $C_{16:1}$ ${omega}5c$ (2.2%). The DNA G+C content of strain $Iso4^T$ was 56.2 mol %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain $Iso4^T$ formed a monophyletic clade in the family Hyphomonadaceae, supported by high bootstrap value and was most closely related to the genus Hyphomonas (92~94%), a member of marine bacteria in the family. The phenotypic, genotypic, and chemotaxonomic evidences also suggest strain $Iso4^T$ represents a novel genus and species in the family Hyphomonadaceattr for which the name Henriciella gen. nov., sp. nov. is proposed. The type strain is $Iso4^T$ (=KCTC $12513^T$ =DSM $19595^T$ =JCM $15116^T$).