An ink composition contains a pigment, a polymer having a structure unit having a diphosphonic acid group, a hydrosoluble solvent, and water, and satisfies the following A and B.A: The pigment is represented by the following chemical formula 1a or chemical formula 1b. As for Chemical formula 1a, the pigment satisfies the relation 1: Y/X≦0.800, where X and Y represent peak intensities at a Bragg (2θ±0.2°) angle in a CuKα X-ray diffraction spectrum, when the pigment is represented by Chemical formula 1b, the pigment satisfies the relation 2: Y′/X′≦0.200, where X′ and Y′ represent peak intensities at a Bragg (2θ±0.2°) angle in a CuKα X-ray diffraction spectrum, B. the structure unit having a diphosphonic acid group is represented by Chemical formula 2.