To provide a mounting structure of a double folding seat for a vehicle that maximizes the efficiency of the space in the vehicle by position change of a turning hinge point of a seat cushion by minimizing the rotation radius required for seat folding of the double folding seat, and improves the appearance by reducing the number of assembling processes by structure improvement of a hinge bracket to be mounted to the seat cushion.

This mounting structure of the double folding seat for the vehicle is a mounting structure of the seat for the vehicle capable of double folding the seat cushion and the seat back. The mounting structure comprises a cushion hinge bracket mounted to the lower part of the seat cushion, a cushion hinge wire turnably fastened to the cushion hinge bracket, and a vehicle body hinge bracket that is mounted to the upper surface of a seat safe arrival section of the vehicle body and turnably fastens the cushion hinge wire. The seat cushion is folded with respect to the vehicle body using the vehicle body hinge bracket as a rotating shaft.