There is provided a bookbinding system which can carry out a process from image formation to glued bookbinding in-line. The bookbinding system comprises a book content data input section 101 to which book content data regarding a content of a book is entered, a cover sheet data input section 101 to which cover sheet data regarding a cover sheet display is entered, a book content image formation section 105 which forms images on recording sheets based on the book content data entered from the book content data input section, a cover sheet display image formation section 105 which forms an image on a case cover based on the cover sheet data entered from the cover sheet data input section, back gluing means 203 for back-gluing the recording sheets on which the images have been formed, and casing means 204 for casing the recording sheets back-glued by the back gluing means with a case cover to bond the sheets.