A crutch comprises a pad enclosing an arm piece, two bow rods connecting the hollow arm piece longitudinally, a handpiece connecting two bow rods transversely, a pipe clamped by the lower portions of two bow rods, an extensible rod inserted beneath the pipe, a tip cushion covering the lower end of the extensible rod, and a mount confining the lower ends of the pipe and two bow rods. A plug is disposed on the upper end of the pipe. The pipe has a plurality of adjusting holes.