To provide a transparent resin composition having excellent heat resistance, optical properties, mechanical properties and proper water vapor permeability, and to provide an optical film which has excellent adhesion and peelability of a protective film of the polarizer when used as the protective film of the polarizer of a liquid crystal display device.

This transparent resin composition comprises a norbornene resin and a polyvinyl alcohol resin. When the norbornene resin is a resin mixture, the resin mixture excludes a resin mixture comprising a polymer obtained by ring opening polymerization of an alicyclic monomer represented by general formula (1) and a polymer obtained by ring opening polymerization of an alicyclic monomer represented by general formula (2).