To provide a method for producing a vinyl chloride-based polymer having sharp particle size distribution and a high bulk specific gravity.

This method for producing a vinyl chloride-based polymer features performing the suspension polymerization of a vinyl chloride-based monomer in an aqueous medium in the presence of both of an oil-soluble polymerization initiator and a dispersion stabilizer by using a grading blade having two or more grids in its longitudinal and transverse directions, having the ratio d (a blade diameter)/D (a tank diameter) of 0.40-0.50 and having the ratio Hb (the height of a bottom paddle blade)/H (the height of the grading blade) of <0.30.