LIGHT BODY STRUCTURE

A construction of a vehicle body of means of transportation which is subjected to external pressure tending to fluctuate. In order to achieve a high riding comfort for passengers by adopting a substantially square cross-sectional shape for securing ample space for the passengers without causing a reduction in the ability to withstand pressure, a multiplicity of substantially square frames (1) each having reinforced portions (A) on two upper corners thereof provided by rounding inner surfaces of the two upper corners and a multiplicity of substantially square frames (2) having reinforced portions (D) on two lower corners thereof provided by rounding inner surfaces of the two lower corners are alternately arranged and connected together by longitudinal structural members (3), and a shell plate (4) is attached to the substantially square frames at their outer surfaces, to provide a substantially square vehicle body.