PURPOSE: To provide a sprinkler connecting joint with which a sprinkler can readily be connected to a water supply pipe in a home in general, and which can prevent water from being trapped in the vicinity of a sprinkler head not only when water flows through the water supply pipe incorporating the sprinkler but also when water is drained from the water supply pipe, so as to eliminate the necessity of an electrical heating wire for keeping warm in a cold district.

CONSTITUTION: A check valve 30 including a valve element 31 for preventing fluid from counterflowing from a conduit 40 connected thereto with a sprinkler head 50, into a joint pipe 20 constituting a sprinkler connecting joint 10, is provided in a part connecting between the joint pipe 20 and the conduit 40. The valve element 31 in the check valve 30 is adapted to block water from flowing into the conduit 40 by the fluid pressure of flame-resistant gas charged in the interior space 41 of the conduit 40, overcoming the pressure of water in the joint pipe 20.