Method for production of water-soluble cationic polymer

A method for the production of a water-soluble cationic polymer comprising polymerizing a water-soluble monomer selected from the group consisting of a cationic acrylate monomer represented by the Formula (1) alone, wherein R.sup.1 and R.sup.2 represent an alkyl group having 1 to 4 carbon atoms, R.sup.3 represents a hydrogen atom or alkyl group having 1 to 4 carbon atoms, and X.sup.- represents a halide ion, sulfate ion, nitrate ion, phosphate ion, carboxylate ion or sulfonate ion, ##STR3## and a mixture of said monomer and another monomer copolymerizable therewith, wherein the concentration of the aqueous solution of said water-soluble monomer is 25 to 80% by weight, in a dispersion medium in the presence of a surfactant by suspension polymerization, wherein said surfactant is a sucrose fatty acid ester whose HLB is 2 to 12 or a polyglycerol fatty acid ester whose HLB is 2 to 16 or a mixture thereof, so as to give said water-soluble cationic polymer having a limiting viscosity of 5 to 15 (.eta.) and a degree of cationization of 3.0 to 5.2.