The invention provides a composition for film molding comprising cellulose fibers, an inorganic layered compound, and a water-soluble polymer, each of which are dispersed on a nano level; a method for producing a cellulose dispersion with which a moisture-resistant film comprising cellulose nanofibers can be produced; a gas-barrier laminate that uses the dispersion; and a packaging material that uses the laminate. A composition for film molding comprising at least cellulose fibers and a swollen inorganic layered compound is produced. The method for producing a cellulose dispersion comprises a step for oxidizing cellulose, a step for preparing cellulose nanofibers by fibrillating the oxidized cellulose, and a step for adding a water-soluble polymer and inorganic particles to the dispersion containing the cellulose nanofibers.