There is provided a polymer compound including a repetitive unit structure represented by the following general formula (2): General formula (2): (where X′ represents a polyalkenyl group; A represents a linear or branched alkylene group having a carbon atom number of 1 to 15, which may be substituted; m represents an integer of 0 to 30; B represents a single bond or an alkylene group which may be substituted; D represents an aromatic ring structure which may be substituted; n represents an integer of 0 to 10; and R represents a hydrogen atom, an alkyl group which may be substituted, or an aromatic ring structure which may be substituted). The polymer compound is suitable for improving dispersibility of a coloring material or solid material in an ink composition or toner composition.