A gasket for fastening the automotive safety belt is disclosed. A plastic material is applied to form a one-piece body comprising a fixing part, a flexible part and a plug part. The plug part of the gasket is inlet into the hole of the suspension sheet of the safety belt for fastening the safety belt so as to avoid the safety belt rolling automatically to bind the human body so close that the chest are oppressed uncomfortably. In addition, the gasket mounted on the outer surface of the buckle of safety belt is made of plastic materials. Even the gasket is touched with human body in use, to adjust and to fasten the safety belt will not result in the human body being hurt from impact. It is much safer for utility.