PURPOSE: To obtain a vinyl chloride polymer excellent in moldability and fabricability, by polymerizing a vinyl chloride monomer in an aqueous medium in the presence of a small amount of an alkyl (meth)acrylate copolymer.

CONSTITUTION: In producing a vinyl chloride polymer by polymerizing a vinyl chloride monomer in an aqueous medium, said polymerization is performed after adding, to the polymerization system, an alkyl methacrylate/alkyl acrylate copolymer in such an amount that its content is 10W5,000ppm based on the formed vinyl chloride polymer. The composition ratio of the copolymer is preferably such that the alkyl methacrylate as the principal component accounts for 60W95wt% and the alkyl acrylate component accounts for 5W40wt%. The polymerization is performed in a temperature range of 30W80°C.