Abstract: A polyvinyl chloride composition comprising 100 parts by weight of a polyvinyl chloride and 5 to 150 parts by weight of a high molecular weight, modified polyester which is prepared by reacting (A) a polyester having a carboxyl group at terminal thereof and containing an ester unit of total carbon atoms of 8 to 10 in the diol component and the dicarboxylic acid component with (B) a compound having epoxy groups at both terminals thereof, said polyvinyl chloride composition having excellent acticoagulant activity and hence being useful for various blood handling devices including blood transmitting tube, as well as other utilities such as packages for foodstuffs as in the conventional polyvinyl chloride composition.