Abstract: A valve timing control apparatus which regulates the movement of an abutting portion in a constraint-free state and prevents the collision between the abutting portion and other members to thereby suppress the generation of hammering sounds. A stopper piston constrains relative rotation between a shoe housing and a vane rotor by being fitted into a taper hole at its most lagged position. Oil pressure chambers apply an oil pressure to the stopper piston in a constraint release direction between the stopper piston and the taper hole. At the most lagged position, a back pressure chamber communicates with an oil lubrication space through communication passages. When the vane rotor is rotated from the most lagged position to an advanced side relative to the shoe housing, the pressure receiving area of a forward end portion of the stopper piston in contact with the oil pressure chamber decreases. On the other hand, communication between the communication passages is interrupted.