The present invention discloses a ratchetable open-ended wrench comprising wrench body and retractable jaw member. The wrench body comprises head with two opposite jaws and a receiving hole. The inner surface of the receiving hole has a sunken slot with an inner circular arc surface. The retractable jaw member is slidably mounted in the sunken slot and has two opposite sides, and one side is directing to the receiving hole and has a second engaging portion. The retractable jaw member and the head are against with an elastic member. The retractable jaw member is able to move from a first position to a second position in the sunken slot, and is able to limit a workpiece to rotate in the receiving hole when at the first position and to allow the workpiece to rotate in the receiving hole when at the second position.