A locking pliers includes a slide bar mounted in both second handle unit and locking unit and comprising a wavy edge facing bottom of the second handle unit, the wavy edge including a rear slot member and a forward hook; and a movable jaw at a forward end of the second handle unit and comprising two intermediate opposite stop members each having an inclined edge, a channel between the stop members with a forward end of the slide bar movably received therein, and a rear stop bar interconnected two sidewalls of a rear portion of the movable jaw, the inclined edges being stopped by bending members on sidewalls of the second handle unit for retaining the stop members in an inoperative position.