Abstract: A vehicular back door fitting mechanism includes a plurality of hinges arranged along one rear pillar with hinge portions turnable with respect to the one rear pillar. A window glass is provided with a cut out at one lower corner thereof so that the uppermost hinge is located at the cut-out part of the window glass. This arrangement of the uppermost hinge permits a hinge span which is longer, resulting in a fitting strength of the back door being increased remarkably. The uppermost hinge is covered with a trim element and at least one other hinge is located below the uppermost hinge, arranged inside of the back door so that they cannot be seen from the outside. This arrangement provides an improved appearance.