To obtain an excellent highly hydrated solid cosmetic composition usable as a base for solid cosmetics and compounded with a raw material overcoming perspiration phenomena and capable of improving the stability of solid cosmetics even if incorporated with much water.

This composition is such one as to be compounded with 1.0-50.0 wt.% of one or more kinds of dimer diol derivatives each obtained by reaction between a dimer diol and an epoxide and also combined with wax. The composition enables perspiration suppression by containing water in a solid cosmetic and controlling the hygroscopicity of a pigment in the solid cosmetic product and improves the stability and mechanical strengths of the solid cosmetic even if incorporated with much water.