A polymer composition wherein an inorganic substance and an organic polymer are firmly consolidated, which is characterized by being produced by polymerizing a vinyl monomer susceptible to radical polymerization in a polymerization system containing a dispersed inorganic substance in the presence of at least one monomer selected from sulfonic acid monomers, sulfonate monomers, or carboxylic acid monomers represented by the general formula [I] ##STR1## wherein R.sub.1 is a hydrogen atom, alkyl group having 1 to 20 carbon atoms, phenyl group, derivative of phenyl group, or halogen atom, X is CONH, ##STR2## COO(CH.sub.2).sub.m or (CH.sub.2).sub.n (wherein R.sub.2 and R.sub.3 are each a hydrogen atom or alkyl group having 1 to 15 carbon atoms, R.sub.4 is an alkylene group having 1 to 15 carbon atoms, m is an integer of 1 to 20, and n is an integer of 0 to 20), and Y is a hydrogen atom, ammonium radical, or an alkali metal atom, or by the general formula [II] ##STR3## wherein R.sub.5 is a hydrogen atom, alkyl group having 1 to 15 carbon atoms, COOZ, halogen atom, phenyl group, or derivative of phenyl group, R.sub.6 is a hydrogen atom, alkyl group having 1 to 15 carbon atoms, COOZ, halogen atom, phenyl group, or derivative of phenyl group, R.sub.7 is a hydrogen atom, alkyl group having 1 to 15 carbon atoms, halogen atom, phenyl group, or derivative of phenyl group, and Z is a hydrogen atom, ammonium radical, or alkali metal atom, or by the general formula [III] ##STR4## wherein R.sub.8 and R.sub.9 are each a hydrogen atom, alkyl group having 1 to 15 carbon atoms, halogen atom, phenyl group, or derivative of phenyl group.