Abstract: An auto lock mechanism of a clock spring for a vehicle is provided. The auto lock mechanism comprises a rolling plate provided in an internal space of the clock spring such that the rolling plate is rotated by a flat cable, and an auto lock unit locking a rotor automatically in such a manner that at a neutral position of the clock spring, where a first locking groove of the rolling plate and a second locking groove of a stator, defining the internal space of the clock spring, overlap with each other, wherein the auto lock unit engages with the first and second overlapping locking grooves to lock the rotor.