The present invention addresses the problem of providing a novel composition for preparing carbon dioxide formulation for external use, said composition being highly spreadable on the skin immediately after mixing two or more agents until applying to the skin while preventing the surface of the applied composition from beginning to solidify, being capable of gelling so that the composition can be separated from the skin without remaining on the skin at the end of the use, and, during use period, generating membrane permeable carbon dioxide in an amount greater than the amount of membrane permeable carbon dioxide generated by a conventional composition for preparing carbon dioxide formulation for external use that comprises known components. Also, the present invention addresses the problem of providing a carbon dioxide formulation for external use and a cosmetic pack that are obtained from the novel composition for preparing carbon dioxide formulation. The composition for preparing carbon dioxide formulation at least comprises, as essential components, a gelling agent that gels in the presence of a magnesium salt, a water-soluble calcium salt, magnesium ion or calcium ion, a carbonic acid salt, a substance that generates an acid when hydrolyzed, a polyhydric alcohol and water.
