A body structure of a vehicle reliably detects, with a side-collision detection sensor disposed on a pillar, a side-collision of a side door of a vehicle body against a pole and particularly a side-collision against a pole in a diagonal direction. A metal bracket that projects toward a vehicle width direction outer side is disposed on an outer side surface in a predetermined position (substantially intermediate position between a front pillar and a center pillar) of a rocker. By setting this metal bracket on the outer side of the rocker, in addition to an impact beam disposed inside a door, an acceleration (sensor G) transmitted to the side-collision detection sensor disposed inside the center pillar increases during a side-collision against a pole in a diagonal direction, so the side-collision state can be reliably and rapidly detected even at a position distant from the center pillar.