Abstract: A control valve having a regeneration function, including a hollow valve body, a plurality of spaced ports provided at the valve body, the ports including a pump port, an actuator port, a regeneration port and a tank port, a hollow main spool movably disposed in the valve body, a regeneration spool movably disposed in the main spool and adapted to be moved by a flow of fluid delivered from a pump through the pump port, a fluid passage provided at the main spool and adapted to communicate the actuator port and the tank port together, the fluid passage being opened or closed by the movement of the regeneration spool, whereby as the regeneration spool is moved by the fluid flow delivered from the pump, a part, to be fed to the tank port, of a flow of fluid emerging from the actuator port is increased, while a part to be fed to the regeneration port is correspondingly decreased.