PURPOSE: To disperse an inorganic pigment, etc., in an organic solvent and to prevent its flocculation and sedimentation by copolymerizing specified two species of vinyl monomers into a dispersant for an organic solvent.

CONSTITUTION: A vinyl monomer A of the general formula I, which has a polyethylene glycol chain, (wherein R1 is alkyl, phenyl or other group of 1W6C, X1 is H or alkyl group of 1W3C, n=2W200 and m=0W100) and a vinyl monomer B of the general formula II (wherein R2 is alkyl, phenyl or other group of 1W24C and X3 is H or alkyl group of 1W3C) are used, and these two species of monomers are copolymerized. Thus obtained dispersant disperses fine powder such as inorganic pigment, organic pigment, etc., steadily in an organic solvent system, prevents the flocculation and sedimentation of the powder, lowers the viscosity of the system and makes the concentration of the powder higher.