A composition for manufacturing a heat ray-shielding polyvinyl chloride film by the steps of obtaining a dispersion liquid by dispersing tungsten oxide nanoparticles expressed by a general formula WOx and/or the composite tungsten oxide nanoparticles expressed by a general formula MyWOz and having a hexaboride crystal structure, and a dispersant, into an organic solvent; obtaining a mixture by mixing a plasticizer for manufacturing a polyvinyl chloride, into this dispersion liquid; and obtaining a composition for manufacturing the heat ray-shielding polyvinyl chloride film by using a vacuum distillation method and removing the organic solvent from this mixture until a concentration of the solvent is 5 wt % or less.