Vehicle air bag system

A vehicle air bag system is provided with an air bag that inflates and unfolds to cover the entire front surface of a front pillar (3). When it is judged based on the detection operation of a collision detection device (10) that there is a risk of colliding with a pedestrian, a hood pop-up device (11) is actuated and the rear end part of the hood (1) moves up, widening the gap between the rear end part and the front windshield (2). Simultaneously, the air bag module (15) is actuated and the air bag (18) expands out from the gap. The air bag inflates and unfolds so as to cover the entire front surface of the front pillar (3) from the base to the upper end thereof.