A vinyl chloride resin composition comprising 100 parts by mass of a vinyl chloride resin and a co-ground mixture of (a) 0.001 to 10 parts by mass of at least one member selected from the group consisting of an organic phosphoric ester compound and a metal salt thereof and (b) 0.001 to 10 parts by mass of a grinding aid. The composition is excellent in transparency, heat stability, and heat discoloration resistance.