Abstract: A packing mounting structure for a vehicle door powered sliding device comprises an elongated guide rail fixed to a side panel of a vehicle body, a sliding door mounted on the body, a powered sliding unit arranged on an interior side of the side panel, a wire cable provided between the sliding door and the powered sliding unit, a pulley holder provided in the vicinity of one end of the guide rail and having a first pulley around which the cable wire is set, a cable hole formed on the side panel in the vicinity of the one end of the guide rail for passing the wire cable through the side panel, a flexible packing member mounted in the cable hole to close a gap between the cable hole and the wire cable. The pulley holder is fixed to the side panel by either of a screw or bolt.