A rubber sheet joining apparatus includes a cutting unit for cutting a ribbon of rubber sheet reinforced with cords to generate rubber sheet strips having different lengths; a sheet overlapping unit for overlapping and joining the rubber sheet strips having different lengths to make an overlapped and joined strip. First holding members hold a front end portion of a following overlapped and joined strip. Second holding members hold a rear end portion of a preceding overlapped and joined strip. Support guides movably support the first holding members relative to the second holding members. An operating unit moves the first holding members relative to the second holding members to butt-join the side surfaces of two successive overlapped and joins strips held respectively by the first holding members and the second holding members to generate a ply sheet.
