The present invention relates to a coated fabric for an air bag obtained by applying an elastomer resin onto at least one side of a woven fabric made from synthetic fiber. The applied amount of the elastomer resin is 25 to 60 g/m.sup.2. The average resin thickness on warp and weft at head top of the woven fabric surface is 8 μm to 45 μm. The number of foams having diameter of 30 μm or larger is 100 or more/cm.sup.2 on the surface of a resin layer.