<p>[Problem] To provide a carboxyl group-containing polymer composition, which has excellent dispersibility in water or the like and gives a neutralized viscous liquid having low viscosity and high transparency. [Solution] A carboxyl group-containing polymer composition comprising, with respect to 100 parts by mass of a carboxyl group-containing polymer obtained by copolymerizing an a,ß-unsaturated carboxylic acid and a compound having at least two ethylenically unsaturated groups, 0.05 to 5 parts by mass of at least one compound selected from a group consisting of (1) a fatty acid A and (2) a fatty acid ester of a fatty acid B and a monohydric alcohol having 1 to 22 carbon atoms.</p>
