Abstract: A fluid flow control valve assembly which comprises a valve housing having defined therein a valve chamber defined therein a valve hole, inflow and outflow ports adapted to be communicated with each other through the valve chamber by way of the valve hole; and a valve rod inserted exteriorly of the housing and into the valve chamber and coupled with a handle for turning the valve rod about a longitudinal axis thereof thereby to move the valve rod in a direction coaxial with the longitudinal axis of the valve rod to adjust an opening of the valve hole. The valve rod includes a valve member formed on one end of the valve rod confronting the valve chamber and axially movably inserted in the valve hole, and a shank portion formed on a generally intermediate portion of the valve rod and slidably, but fluid-tightly sealing the valve chamber.