A pipe joint comprises a pipe (3) formed with an annular projection (1) on a connection end portion thereof, a member having a socket (4) including a cylindrical portion for receiving the pipe therein and formed with apertures (5) in the cylindrical portion, and a resilient stopper (10) having circular-arc ridges (7a) fittable in the respective apertures of the socket to project inward. The stopper extends axially of the pipe and has portions which, when the stopper is mounted on the cylindrical portion of the socket, are beyond 180<o> from the direction of mounting and at least have a circular-arc form to extend along the outer periphery of the cylindrical portion. The stopper further has an assembling error preventing flange on the pipe insertion side of the ridges or on the opposite side thereof. The socket is formed with a protrusion for the flange to come into contact with. <IMAGE>
