To provide an airbag system for pedestrians capable of completing the expansion in such a way that a pillar protection portions in the left and right of an airbag cover a pillar portion quickly without flipping.

The airbag 46 includes a cowl louver protection portion 50 and a pillar protection portion 49. When the airbag 46 completely expands, the cowl louver protection portion 50 covers the upper part of a cowl louver 18 and the pillar protection portion 49 extends from the left and right of the cowl louver protection portion 50 to cover at least the front side in the vicinity of the bottom end of left and right front pillars. A tether 61 is placed in the edge of each pillar protection portion 49L of the airbag 46 close to the cowl louver protection portion 50. The tether 61 extends from the outer periphery apart from the cowl louver protection portion 50. The front edge of the tether 6 is fixed to the vehicle body 1, thereby reducing the flipping of the pillar protection portion 49L when the airbag 46 expands.