To provide a yellow dye having a hue with high clarity suitable for inkjet recording, high various fastness of records and excellent preservation stability of an ink composition when preparing the ink composition and to provide the ink composition comprising the yellow dye.

A water-soluble azo compound is represented by formula (1) (wherein, R1 and R2 represent each independently a hydrogen atom, a 1-4C alkyl group or a 1-4C alkoxy group; and x represents an integer of 5-11) as a free acid or a salt thereof. The ink composition comprises the compound or a salt thereof.