To surely reduce a load noise.

A partition panel 10 is formed into a circular arc projection protruding toward the front of a body in a vehicle body lateral view. In the vehicle front view, a V-shaped bead 20 is formed. On the vehicle body rear part, if the lateral direction of the vehicle body is torsionally vibrated in the vertical direction, a tensile force works on a reinforcing means arranged in the partition panel 10 on the side, on which the volume of a rear part vehicle interior space is deformed compressedly, among the body left and right side, and the corresponding part in the partition panel 10 is vibrated toward the vehicle rear side. On the other side, on which the volume of the vehicle interior rear part is deformed expandedly, among the body left and right sides, a compressive force works on the reinforcing means arranged in the partition panel 10, and the corresponding part of the partition panel 10 is vibrated toward the vehicle front side.