PURPOSE: To provide a chassis for a vehicle such as a pickup truck and a van, capable of solving the problems of loading, unloading, and positioning.

CONSTITUTION: This vehicle chassis is provided with a front part 20 supporting an engine and front wheels, a back part 22 comprising a pair of parallel side frames holding a floor, which is made movable between the required positions in the horizontal state, between the positions, a torque box 30 connected with the front and back parts, a roll bar 88 horizontally disposed above the torque box, support bars 90, 92 connecting the roll bar to the side frames, and a shaft mounting flange installed in the one end of an arm. The vehicle chassis is composed of a tail arm assembly formed by mounting the other end of a tail arm rotatably on the side frames of the chassis, and a back suspension supporting assembly installed to the side frames.