Floor structure of vehicle

A floor structure of a vehicle according to the present invention performs reinforcement, utilizes a ridge part, a board part, and a closed section part arranged at the lower part of a step part to suppress vertical vibration generated on the floor, enables the vibration from not crossing the step part to transmit to a rear floor, and enables impact load subjected through a passage part to flow to the side of a lower bridge part, thereby improving integral rigidity of the vehicle body and the floor, and improving installing strength of vehicle members. The floor structure of the vehicle comprises a front floor and a rear floor, the central part of the front floor is provided with a protruding passage part extending along the front-rear direction of the vehicle, the front part of the rear floor is provided with a step part of longitudinal wall extending in the upward direction of the vehicle, the lower part of the step part is provided with a ridge part and a board part formed at the lower side of the ridge part, the ridge part, viewed from the front side of the vehicle, extends from the passage part to the lower bridge part at the outer side of the vehicle width direction, so as to connect the passage part and the lower bridge part, and has an inclined part inclining downwards, the lower part of the step part is provided with a section, i.e., a closed section part, which is perpendicular to the length direction of the ridge part.