A pigment dispersing agent wherein a quinophthalone structure is bonded to a triazine structure through an arylene group or a heteroaromatic ring and a basic functional group is bonded to triazine ring through a connecting group which pigment dispersing agent improves an ink or a coating in fluidity and is effective for preparing a product having a low viscosity and low thixotropic properties and having excellent properties such as tinting strength, transparency and viscosity stability with the passage of time, and a pigment composition and a pigment dispersion containing the same.