PURPOSE: To attain light weight, cost reduction, and sufficient liquidtightness, in a branched pipe fitting tightened from both ends of a plurality of pipe bodies having pipe connecting ports on the circumferential faces by making pipe bodies of resin material, and providing a reinforcing member extending from one end to the other end and partially supporting the tightening force both sides.

CONSTITUTION: A branched pipe fitting 1 is formed into a long pipe-body by connecting pipe bodies 21-25 in order in the axial direction. Each pipe body 2 is made of resin material. Respective pipe 2 bodies are fitted each other with cutout parts provided on the opening end edges, and O-rings 3 are provided between. A cylindrical reinforcing member 13 is arranged on the inner circumferential face of each pipe body 2. The member 13 is for example made of metal, especially, stainless steel, and has sufficient compressive strength and sufficient lateral rigidity. The member 13 is provided with communicating parts 15, the communicating parts 15 are opposite to the communicating parts 16 of respective connecting ports 9. As a result of this, weight is lightened, cost is reduced, bending is avoided, and sufficient liquidtightness is insured.