The film-forming agent of the invention is a blend of a silica organosol, of which the silica particles have a specified specific surface area and specified densities of surface groups including silanol groups, alkoxy groups and trimethyl silyl groups, and a diorganopolysiloxane of a specified viscosity terminated at each molecular chain end with a silanolic hydroxy group. The film-forming agent is useful as a skin-care preparation for preventing chapping of hands of people having frequent occasions of contacting with water to exhibit durable water repellency.