Provided are a water-soluble ginger root extract which is a water extract or a hydrous alcohol extract of a ginger root and is substantially free of gingerols; and a hair growth inhibitor and a preparation for external use each containing the extract. The water-soluble ginger root extract of the present invention causes less skin irritation because of being substantially free of gingerols, and has excellent body-hair growth inhibiting effects, so that it is useful as a hair grown inhibitor and a preparation for external use, each having a high degree of safety.