To provide a resin composition meeting the demand of higher performances including water vapor-barrier property, heat resistance, oil resistance, mechanical properties, transparency and processability, and to provide a resin film prepared by forming the resin composition.

The resin composition is a crosslinkable norbornene resin composition includes 100 pts.wt. of a norbornene ring-opened polymer hydrogenated product (1) and 0.01-20 pts.wt. of an organic peroxide (2); wherein the norbornene ring-opened polymer hydrogenated product (1), which is 110-145C in melting point, 50,000-200,000 in weight-average molecular weight determined by gel permeation chromatography and 1.5-10.0 in the ratio of weight-average molecular weight to number-average molecular weight, is such as to be obtained by ring-opening polymerization of a polymerizable monomers comprising 90-100 wt.% of 2-norbornene (1-1) and 10-0 wt.% of a substituted norbornene monomer (1-2) followed by conducting a hydrogenation of the resultant polymer.