PURPOSE: The titled composition having a low degree of polymerization and excellent processability and flowability, comprising a specified vinyl chloride polymer and a specified methyl methacrylate polymer.

CONSTITUTION: A vinyl chloride resin composition comprising 100pts.wt. vinyl chloride polymer (A) which contains at least 80wt% vinyl chloride, and consists of 5W100wt% polymer with an average degree of polymerization of 300W700 and 90W0wt% polymer with an average degree of polymerization higher than 700, and 0.1W30pts.wt. methyl methacrylate polymer (B) which contains at least 40wt% methyl methacrylate and has a reduced viscosity ηsp/C, measured at 25°C on a solution of 0.1g polymer in 100ml chloroform, of 0.1/2l/g. This composition can be used for the manufacture of a film, a sheet, and a plate by vacuum molding, for a large molded product by injection which requires high flowability of the material, and for calendering of a heavy section of extruded high density foam.