A method for producing a polymer solution containing vinylamine units

The present invention provides a method of high performance and good handling polyvinyl amine solution industrially produced efficiently. After the N- vinylcarboxylic acid amide having a weight average molecular weight of the monomer units is at least 5 Polymer Mw / number average molecular weight Mn, an aqueous solution standing adiabatic polymerization method, a base and an anti-gelling agent in the presence of the polymer will be subjected to hydrolysis in an aqueous solvent. In a preferred embodiment of the present invention, after manufacturing a (co) polymer, powdered and dried, to give a nonvolatile content of 0.1 to 12 mass% of the polymer powder, the obtained powder was stored or transported to the place of use of the polymer solution , in the presence of a base and an anti-gelling agent, or hydrolysis in an aqueous solvent in the polymer solution is required when using the properties of the polymer solution.