Abstract: The object of the present invention is to provide a production method of water-soluble silane derivatives, the separation and purification of which are easy, and the reaction for which can be conducted under an industrially practicable temperature condition (under the temperature condition of 90° C. or lower) and to provide compounds with which solid gelatinous external preparations, with excellent stability against a temperature change and against an effect of additives and with excellent usability, can be prepared. The water-soluble silane derivative could be formed by the substitution reaction of a metal alkoxide with a polyhydric alcohol under the presence of a solid catalyst. According to this production method, the separation of the catalyst from the product is very easy, and the reaction can be carried out under the temperature condition of 90° C. or lower.