To prevent water leakage from a back door hinge fitting part by providing an upper flange in a back door hinge fitting hole provided in a roof panel.

A back door of a vehicle is connected to a rotary member 4' of a back door hinge 4 by bolt and nut, and a fixing bolt 5 fitted to a base member 4" is inserted in a fitting hole 7 of a back door hinge fitting part 6 provided on a roof panel 3. The fixing bolt 5 is put in the connecting state by a nut fixed to the back door hinge fitting part 6. The back door hinge fitting hole 7 provided in the back door hinge fitting part 6 forms an upper flange 8. At the time of connection, the upper flange 8 is inserted in a fixing bolt fitting hole provided in the back door hinge 4. Thus, it is possible to prevent water from leaking from the back door hinge fitting hole 7 into the interior of the car compartment.