A vehicle body structure in which the rigidity of a flat floor panel is increased by increasing the rigidity of intersecting portions between a cross member and floor frames. A plurality of floor frames extending in the longitudinal direction of a vehicle body are aligned in straight rows in the longitudinal direction on either sides of a cross member extending in the vehicle width direction. Terminal ends of the plurality of floor frames are positioned in proximity to the cross member. The intersecting portions between the floor frames and the cross member are joined together by T-shaped connecting members in order to increase rigidity.