To provide a connection structure of a bead wire rod, capable of improving the reliability of connection between both edges of the bead wire rod and a connector in the forming operation a bead cord.

Both the edges of the bead wire rod are inserted from both edge openings of a cylindrical body, an engagement portion comprised of recess portions or protrusion portions or recess and protrusion portions is formed around the outer periphery of the bead wire rod on both edge side, and the cylindrical body is formed with protrusions protruding in a direction of the bead wire rod. Besides, the engagement portion of the bead wire rod is formed with the ring-like or spiral recesses or protrusions or recesses and protrusion portions around the outer periphery of the bead wire rod, the protrusion of the cylindrical body has the edge cut upward in a center-axis direction of the cylindrical body, which is composed of a jaw cut upward facing the center side of the cylindrical body in a longitudinal direction, and wherein a block portion blocking the edge of the bead wire rod is formed in the center of the cylindrical body in a longitudinal direction.