The present invention discloses a pair of adjustable pliers, comprising a first
handle and a second
handle, both of which have a gripping part arranged at a front end thereof, the two gripping parts forming a jaw span, the first
handle and the second handle being arranged in an intersectional manner and relatively fixed via a connecting mechanism, wherein the second handle has an elongated rack slot at a position of the connecting mechanism, and the rack slot is provided with a toothed rack on an inner side part thereof. The connecting mechanism comprises a positioning snap piece arranged inside the rack slot and a link mechanism connected with the positioning snap piece, the positioning snap piece has lateral teeth which are engaged with the toothed rack on the rack slot, the link mechanism is provided to drive the positioning snap piece to rotate and disengage the lateral teeth on the positioning snap piece from the toothed rack. Thus the first handle can move relative to the second handle along the rack slot through the movement of the connecting mechanism. The link mechanism comprises a trigger shaft connected with the positioning snap piece, and the trigger shaft has a trigger part thereon. The present invention has the advantages that the right handle can be directly pushed to achieve the quick one-way adjustment, which is convenient and saves effort compared to the ordinary water pump pliers that need two-handed adjustment.