A locking mechanism includes a tray to receive a hard disk drive and a locking apparatus. The locking apparatus includes a base attached to a front wall of the tray, a handle pivotally connected to the base, and a locking member attached to the base. The base defines a receiving chamber and a mounting hole in communication with the receiving chamber. The locking member includes a sliding portion slidably received in the receiving chamber of the base to impel the handle to pivot relative to the base, and a locking tongue attached to the sliding portion. Movement of the locking tongue relative to the mounting hole causes the locking mechanism to toggle between a locked and unlocked position.