To provide a pipe fitting which allows a connection between fluid pipes to be made easily, can prevent leakage of fluid, and allows easy re- connecting work.

This plug-in pipe joint for a fluid pipe includes a joint pipe main body 10 having a duct on its axis; a pipe support cylinder 20 mounted inside the joint pipe main body 10; a stopper ring 40, with an engaging surface which is engaged with the outer surface of the fluid pipe 70 fitted over the pipe support cylinder 20, and with an outside inclined face, stored in a storage part in the joint pipe main body 10; a fastening ring 50 having an inclined face which abuts to the inclined face of the stopper ring 40 and stored in the storage part in the joint pipe main body 10; and a holding nut 60 fitted to the end of the joint pipe main body 10 to press the stopper ring 40 and the fastening ring 50. In this case, connection of the fluid pipe 70 can be made by inserting the end 71 of the fluid pipe 70 between the holding nut 60, the fastening ring 50, the stopper ring 40, the joint pipe main body 10, and the pipe support cylinder 20 mounted inside the joint pipe main body 10.