A method for electroplating nonconductive material, comprising the steps of bringing a nonconductive material into contact with an acidic hydrosol solution containing a palladium compound, a stannous compound, and a copper compound; and bringing the material into contact with an aqueous alkaline solution before electroplating. When this method is used, a good electroplated film having an excellent decorative appearance can be formed on the surface of such a nonconductive material as molded plastic parts, etc., having a large area without requiring any electroless plating process.