Abstract: A vehicle lock device is disclosed to impede a person from using a wrong key. When a key rotor is forcibly turned by a wrong key, the key rotor with the aid of tumblers turns a sleeve. The sleeve then moves slide members backward through a cooperative cam action. The front ends of the slide members have cam faces that are designed to correspond to guide grooves of the sleeve and recess portions of a rotor case. The backward movement of the slide members disengages a rotation transmitting member from the key rotor so that the key rotor is in an idle state.