A pigment dispersing agent of the formula (1) capable of providing a printing ink or a coating composition excellent in fluidity and dispersion stability and a dry coating excellent in gloss, a pigment composition containing the same and a pigment dispersion containing the same, wherein X1 is —NH—, —O—, —CONH—, —SO2NH—, —CH2NH—, —CH2NHCOCH2NH— or —X3—Y—X4—, X2 and X4 are —NH— or —O—, X3 is —CONH—, —SO2NH—, —CH2NH—, —NHCO— or —NHSO2—, Y is an alkylene group, an alkenylene group or an arylene group, Z is —SO3M or —COOM, R1 is a heterocyclic ring residue or an aromatic ring residue, Q is —O—R2, —NH—R2, a halogen group, —X1—R1 or —X2—Y-Z, R2 is a hydrogen atom, an alkyl group or an alkenyl group, and M is one equivalent of a monovalent to trivalent cation.