Provided are an ink composition with superlative fastness and excellent gray balance from high density regions to low density regions, an inkjet printing ink using said ink composition, and an inkjet printing method using said inkjet printing ink. An ink composition comprising at least two kinds of water-soluble long wavelength dyes for which the maximum wavelength for the absorption spectrum in an aqueous solvent is 550 - 700 nm, wherein at least one of the water-soluble long wavelength dyes is a first water-soluble long wavelength dye that is an azo compound represented by formula (1), and at least one of said water-soluble long wavelength dyes is a second water-soluble long wavelength dye that differs from the first water-soluble long wavelength dye and the second water-soluble long wavelength dye is a compound having two - four azo groups in a single molecule that are conjugated with each other; an inkjet printing ink using said ink composition; and an inkjet printing method using said inkjet printing ink. (In formula (1), A represents a substituted or unsubstituted aryl group, or substituted or unsubstituted nitrogen-containing 5-membered heterocyclic group. G represents a nitrogen atom or -C(R2)=. R2 represents a hydrogen atom, sulfo group, carboxyl groups, substituted or unsubstituted carbamoyl group, or cyano group. Y2, Y3 and Y4 each independently represent a hydrogen atom or monovalent substituent. Y2, Y3 and Y4 can be bonded to each other to form a ring. Y2, Y3 and Y4 never all represent hydrogen atoms at the same time. The Ms each independently represent a hydrogen atom or a monovalent counteraction.