A dilatant characteristic portion, that is structured to include a dilatant characteristic resin material, is provided at a portion of a webbing from a lap webbing portion to a portion that is further toward a shoulder webbing side than a through-hole of a tongue in a webbing applied state. When the webbing is pushed against an inner peripheral portion of the through-hole due to a body of a passenger pulling the webbing when a vehicle suddenly decelerates, the dilatant characteristic resin material hardens due to this load. Due thereto, flexure of the webbing when the webbing attempts to pass-through the through-hole and move is restricted, and therefore, the shoulder webbing passing-through the through-hole and moving toward a waist portion side of the passenger can be prevented or suppressed.