A Continuous Variable Valve Timing (CVVT) apparatus for an engine may include a housing, a rotor disposed to be rotatable relative to the housing, a locking pin passing through a facing relatively rotating surface between the housing and the rotor by elastic force so as to restrict rotation of the rotor relative to the housing by linear movement, and an oil control valve disposed such that oil is supplied to an advance chamber and a delay chamber provided between the rotor and the housing, in which, when a control duty value applied to the oil control valve is “0”, the oil control valve is fixed in a state in which the oil is supplied to the advance chamber.