A water-saving valve assembly has a base, a control valve device and a buffer device. The control valve device is mounted in the base. The water-saving valve assembly is mounted on an exit of a water pipe. Users can control the flowing out or stopping of water in the water pipe via the control valve device. The buffer device provides a gradual effect of switching off and can effectively reduce positive and negative pressure waves generated in the water pipe. Noises and damage to the water pipe are also prevented.