A composition for use in preparation of carbon dioxide gel for external use of the present invention is used for preparing a carbon dioxide gel for external use including carbon dioxide dissolved therein in a substantial non-bubble form. The composition includes a granular material and a viscous material to be mixed with the granular material. In a first composition for use in preparation of carbon dioxide gel for external use, the granular material includes a weak acid and a calcium ion trapping agent as essential components, whereas the viscous material includes calcium carbonate, a gelling agent gelated by calcium ions and water as essential components. In a second composition for use in preparation of carbon dioxide gel for external use, the granular material includes a weak acid and a dispersant as essential components, whereas the viscous material includes calcium carbonate, a gelling agent gelated by calcium ions, a calcium ion trapping agent and water as essential components.