It is an object of the present invention to provide an ink composition with excellent gas resistance, fixability, and bronzing resistance, as well as a recording method and recorded matter in which this ink composition is used. The present invention achieves this object by means of an ink composition in which a pigment is dispersed in a solvent, and a copolymer, which contains structural units originating in an aromatic compound monomer and structural units originating in a C.sub.5 or higher diene compound and/or structural units originating in a non-diene compound, is included, wherein the copolymer has a sulfonic acid group, and the proportion of structural units originating in the aromatic compound monomer is 30 to 60 wt % with respect to the weight of the copolymer (100 wt %). In the present invention, styrene, .alpha.-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, chlorostyrene, or vinyl benzoate is selected as the above-mentioned aromatic compound monomer.