Abstract: An automotive door trim mounting structure comprises a center pillar disposed between a front door and a rear door, and has the rear door hinged to be opened and closed. A rear door trim includes a main body portion mounted to an interior side of the rear door to cover the interior side, and an extension formed at the front end of the main body portion which extends toward the front door so as to cover the interior side of the center pillar. As the center pillar is covered with the rear door trim, the front and rear door trims appear as if they are continuous, thus obtaining a preferred interior design for the automobile.