Polymer or copolymer of vinyl chloride having superior properties can be produced by suspension-polymerizing vinyl chloride or a mixture thereof with another vinyl monomer, at first, in the presence of an oil-soluble radical initiator, and thereafter, when the percentage of polymerization of the resulting polymer has reached about 15% to about 80%, subjecting the polymer to a further polymerization in the presence of a water-soluble radical initiator.The product thus obtained has both the merits resulting from suspension polymerization and emulsion one. It has an extremely high absorptivity of plasticizer, easy processability, and film made therefrom has substantially no fish eye.