In a process for producing a polymer of monoallylamine comprising polymerizing monoallylamine, the polymerization is carried out using as a monomer inorganic acid salts (e.g., hydrochloride, sulfate, etc.) of monoallylamine in the presence of an azo type radical initiator such as 2,2'-azobis(2-methylpropionamidoxime), 2,2'-azobis(2-methyl- propionhydroxamic acid), etc. in a polar solvent such as water, an aqueous solution of zinc chloride, etc.
By the process, polymers of monoallylamine having a high degree of polymrization can be obtained in high yield.