An airbag includes a bag portion and a plain cloth portion. The bag portion is woven by double weave. The plain cloth portion is woven by plain weave at an edge of the bag portion. The bag portion and the plain cloth portion include warp threads and filling threads. The bag portion and the plain cloth portion are woven by a one piece woven method to satisfy: (1) each warp thread is not over four consecutive filling threads and each filling thread is not over four consecutive warp threads around a border between the bag portion and the plain cloth portion; and (2) every two adjacent warp threads are not over two adjacent filling threads and every two adjacent filling threads are not over two adjacent warp threads around the border.