A protective tube connection structure includes a protective tube through which an electric wire is inserted and has alternately large diameter portions and small diameter portions; and a covering member where an end portion of the protective tube is fixed, the electric wire led out from the end portion being disposed inside the body portion. A wire support portion is provided on a bottom plate portion vertically below the covering member such that the electric wire led out from the end portion of the protective tube is placed on the wire support portion at first and the wire support portion is located vertically above an inner surface of the small-diameter portion on an endmost side.