In a webbing guide structure, when a take-up stopper has made abutted to a contact face of a webbing guide due to take-up force acting on a webbing arising from a spiral spring of a webbing take-up device, a rigid portion of the webbing extends out from the webbing guide towards the vehicle front-side, and a portion of the rigid portion further towards an tip end than the take-up stopper projects out from the rear seat back to the vehicle front-side. Due to utilizing biasing force of the spiral spring to project the rigid portion out from the rear seat back to the vehicle front-side, the need to provide a separate mechanism to project the rigid portion out can accordingly be eliminated. A gap between the rear seat back and the webbing can thereby be provided by employing a simple structure.