A base fabric for an air bag is provided which is light-weight, flexible, superior in stowability, air shieldability, heat resistance and flame retardancy, further superior in the adhesion to resin and difficult to undergo stitch dislocation and fray. The air bag base fabric comprises a synthetic fiber fabric at least one surface of which is coated with resin. The resin is present also over at least 85% of the total area of an intertwined portion interface as a warp-weft crossing portion of the synthetic fiber fabric.