To provide a pigment dispersant which is excellent in the ability to disperse a pigment and is capable of giving a molding having an excellent appearance and to provide a masterbatch composition containing the pigment dispersion and a pigment.

The pigment dispersant comprises (a) an ethylene/α-olefin copolymer having a number-average molecular weight in the range of 500-5,000 as measured by gel permeation chromatography (GPC) and satisfying the relationship: 0.501xD-360≥ Tc [wherein Tc (°C) is the crystallization temperature as determined with a scanning colorimeter (DSC) at a temperature lowering rate of 2°C/min, and D (kg/m3) is the density as measured by a density gradient tube method].