Disclosed is a valve sealant fitting of high quality, which not only ensures rapid and easy injection of a sealant but also maximizes an effect of preventing a leakage. That is, the present invention provides a valve sealant fitting, which comprises, sequentially assembles and couples: a sealant body 10 having an insert coupling groove 12 with a sealing O-ring 12a mounted on an inner wall of the body, a sealant exit port 13 with a small diameter and a sloped injection port at a lower end of the body, and an exit port side ball 14 mounted at a bottom of the exit port 13; an insert 20 having an intermediate sealant movement path 21 for guiding the sealant to be injected toward an inner center of the insert and having a sealed port 22 and a coil spring 23 interposed at a lower end of the insert; and an upper end cap 30 having a sealant injection port 31 with a small diameter mounted on an upper end of the insert 20 and having an injection port side ball 32 mounted below the injection port 31.