To provide a liquid composition capable of forming a catalyst layer that is excellent in resistance to hydrogen peroxide and peroxide radicals, can further increase the output voltage of a membrane/electrode assembly, and can maintain a high output voltage for a long period of time; a method for its production; and a membrane electrode assembly for a polymer electrolyte fuel cell using said liquid composition. Provided is a liquid composition to be used for forming a catalyst layer constituting an electrode of a membrane electrode assembly for a polymer electrolyte fuel cell, wherein the liquid composition comprises a liquid medium, a fluoropolymer (H) having sulfonic acid groups and ring structures, and trivalent or tetravalent cerium ions, and the content of the trivalent or tetravalent cerium ions is from 1.6 to 23.3 mol % to the sulfonic acid groups (100 mol %).