An automotive outboard air bag system (30) is provided in which a belt-like strap (34) is provided at substantially a center within an air bag (33) to extend from an upper end portion (33a) to a lower end portion (33b) of the air bag (33) with sides of the strap (34) being made to extend in a longitudinal direction of a vehicle body, front and rear side edges (34a, 34b) of the strap (34) are connected to an inner circumference (33c) of the air bag (33) to thereby form front and rear constricted portions (35) on front and rear central portions of the air bag (33), and left and right convexly curved portions (36) which can come into contact with an outer surface (12b) of a windshield (12) and a garnish (18b) of a front pillar (18), respectively, are provided on both sides of the rear constricted portion (35).