A bookbinding system to produce booklets, including: an image forming section; a first conveyance route of the sheet carrying the image; a sheet storing section which stores sheets on which no image is going to be formed; a second conveyance route to connect the sheet storing section and the first conveyance route; a notching section which forms notches on edges of the sheets; and a bookbinding section which accumulates the sheets to form a sheet bundle, and adhere a cover sheet to the sheet bundle to become a booklet, wherein the image forming section is placed upstream of a merging point of the first and second conveyance routes, with respect to a sheet conveyance direction of the first conveyance route, wherein the notching section is placed downstream of the merging point; and the bookbinding section is placed downstream of the notching section, with respect to the sheet conveyance direction.