Provided are a coating composition for forming a gas barrier layer as configured such that a specific compound having two or more 5-membered cyclic carbonate groups and a compound having two or more amino groups are reactable at an equivalent ratio of functional groups of 0.8 to 1.25 to form the gas barrier layer with a polyhydroxyurethane resin as a principal component; a gas barrier film formed of a single layer or multiple layers, at least one of the layer or layers that forms or form the film is a layer that exhibits gas barrier properties, and the layer is formed of a polyhydroxyurethane resin having a specific chemical structure; and a production method of a film having gas barrier properties. Owing to the use of the specific polyhydroxyurethane resin, the coating composition, gas barrier film and production method readily enable to reduce moisture-dependent variations in gas barrier properties, to avoid the production of noxious fumes upon incineration disposal, to provide excellent processability, and to lower the pollutant load on the environment.