Abstract: A bead lock apparatus incorporating in a tire building apparatus and a method of locking a bead ring by using the bead lock apparatus for transferring a bead ring from a bead setter engaging the inner circumferential surface of the bead ring to the tire building apparatus at a predetermined position thereon. The bead lock apparatus includes a plurality of first bead lock segments positioned corresponding to pawl members forming the bead setter and circumferentially spaced from each other with predetermined distances, and a plurality of second bead lock segments positioned between the first bead lock segments in the same plane and circumferentially spaced from each other with predetermined distances. The bead lock apparatus further includes driving devices for displacing the first and second bead lock segments, respectively, to expand and contract independently from each other.