A passenger protecting apparatus that prevents a submarine phenomenon of the passenger by the use of an air belt, or that can protect the passenger by applying a pretension to the webbing. The apparatus includes a seat cushion that includes a seat pad, and an air belt disposed under the seat pad. The air belt includes a buckle and a lap anchor. The rear end on the right and the left of the air belt are connected to the buckle and the lap anchor via a wire respectively. Upon collision, the air belt is inflated and the front portion of the seat pad is pushed up so that a submarine phenomenon is prevented and the buckle and the lap anchor are pulled down.