A green tire forming apparatus comprising: a cylindrical shaping drum on which a tire component including a carcass ply is wound; a pair of bead core holding devices disposed on both outer sides of the shaping drum in a drum axial direction so as to hold, via the tire component, inner peripheral surfaces of a pair of bead cores mounted on external portions of the tire component; turning-up devices disposed on both outer sides of the pair of bead core holding devices, the turning-up devices configured to turn up a pair of protruding portions, of the tire component, which protrude outwardly of the bead cores in the drum axial direction, in a drum-radially-outward direction; and a pair of driving devices configured to move the turning-up devices in the drum axial direction, characterised in that the turning-up devices are mounted, in an alternative manner, as one of a first turning-up device including a pair of bladders configured to expand to turn up the pair of protruding portions outwardly in a drum radial direction, and pressing members configured to be driven by the driving devices to move inwardly in the drum axial direction and to press the expanded bladders inwardly in the drum axial direction, and a second turning-up device including a pair of sliding members configured to be driven by the driving devices to be movable in the drum axial direction, and a plurality of turning-up arms configured to turn up the pair of protruding portions according to movement of the sliding members in the drum axial direction. a cylindrical shaping drum on which a tire component including a carcass ply is wound; a pair of bead core holding devices disposed on both outer sides of the shaping drum in a drum axial direction so as to hold, via the tire component, inner peripheral surfaces of a pair of bead cores mounted on external portions of the tire component; turning-up devices disposed on both outer sides of the pair of bead core holding devices, the turning-up devices configured to turn up a pair of protruding portions, of the tire component, which protrude outwardly of the bead cores in the drum axial direction, in a drum-radially-outward direction; and a pair of driving devices configured to move the turning-up devices in the drum axial direction, characterised in that the turning-up devices are mounted, in an alternative manner, as one of a first turning-up device including a pair of bladders configured to expand to turn up the pair of protruding portions outwardly in a drum radial direction, and pressing members configured to be driven by the driving devices to move inwardly in the drum axial direction and to press the expanded bladders inwardly in the drum axial direction, and a second turning-up device including a pair of sliding members configured to be driven by the driving devices to be movable in the drum axial direction, and a plurality of turning-up arms configured to turn up the pair of protruding portions according to movement of the sliding members in the drum axial direction. a first turning-up device including a pair of bladders configured to expand to turn up the pair of protruding portions outwardly in a drum radial direction, and pressing members configured to be driven by the driving devices to move inwardly in the drum axial direction and to press the expanded bladders inwardly in the drum axial direction, and a second turning-up device including a pair of sliding members configured to be driven by the driving devices to be movable in the drum axial direction, and a plurality of turning-up arms configured to turn up the pair of protruding portions according to movement of the sliding members in the drum axial direction.