A shower head includes a main body, a mounting seat, a locking nut, a connecting disk, an O-ring, a gasket, a water outlet faceplate, an adjusting bolt, and a connector unit. Thus, the connecting disk is moved toward the main body by rotation of the adjusting bolt so that the O-ring is moved upward with the connecting disk and closely urged on the inner wall of the main body, thereby forming a closely sealing effect between the connecting disk and the inner wall of the main body.