PURPOSE: To reduce parts in number by forming a frame member with an inner and an outer lift gate panel and a member outer panel combined with an inner reinforcement panel which is formed with an opening corresponding to a vertical window pane in a back door structure for a vehicle, which is furnished with the vertical window pane under a back window.

CONSTITUTION: The lower support section of a vertical window pane 4 is formed into a closed cross section 11 by the use of a lift gate outer panel 6, a lift gate inner panel 7 and an inner reinforcement 8. The upper support section of the vertical window pane 4 is formed into a closed cross section 12 by the use of a member outer panel 9 and the inner reinforcement 8. The upper end of the vertical window pane 4 is covered by a lift gate garnish panel 5 so as to be fitted on, and the outside of its lower end is covered by a mole 13 so as to be fitted on.