The present invention relates to a water-soluble azo compound represented by the following formula (1) [KA 1] ##STR00001## (wherein, A represents a hydroxyl group, a morpholino group, an amino group, an aliphatic amine residue which may have a substituent, aromatic amine residue which may have a substituent, a phenoxy group which may have a substituent or an alkoxy group which may have a substituent, R.sub.1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R.sub.2 represents a substituent selected from a hydrogen atom, a halogen atom, a nitro group and a hydroxyl group, n represents an integer number of 1 to 3, respectively) as free acid and an ink composition comprising the same. Said azo compound has hue having high vividness suitable for inkjet recording, said ink composition is excellent in storage stability, and an inkjet recorded article by using this is excellent in fastnesses such as moisture fastness, ozone gas fastness and light fastness.