To provide a reinforcing-bar connection method and a connector allowing the reinforcing-bar connection method to be achieved, and to provide a connecting reinforcing-bar using the connector and a method for manufacturing the same.

In a reinforcing-bar connection method, large diameter parts 11, 21 are configured at the tips of reinforcing-bars 1, 2 to be connected with each other, respectively, and the large diameter parts are fixed. A reinforcing-bar connector includes: a cylindrical sleeve body A having an inner diameter allowing loose insertion of the large diameter part; and seal members A1, A2 each for closing a clearance between each of both end openings of the sleeve body and each of the reinforcing bars at the opening. At least one grout material injection hole is provided in a part of the sleeve body. A connecting reinforcing-bar is provided with large-diameter parts at both ends thereof, and a first sleeve body is attached to one end of the reinforcing bar while a second sleeve body is attached to the other end of the reinforcing bar. In a method for manufacturing the connecting reinforcing-bar, any of the first sleeve body with a female screw part directed to the tip of the reinforcing-bar and he second sleeve body with a male screw part directed to the tip of the reinforcing-bar is selectively attached to each of both ends of the reinforcing-bar and the large dimeter parts are configured at both ends of the reinforcing-bar.