Abstract: The present ilylltivllj provides-a pneumatic shock absorber fitted with an ancillary air chamber. The miajor fatuire of such know-how is that pneumatic shock absorber is fitted with an ancillary air chamber interconnected to or separated from air chamber of cylinder body. And, a floating piston is mounted into the ancillary air chamber. Based on this imiiovative design when When the extensible axle of pneumatic shock absorber starts to shrink, the effective flexible travel can be extended in tune with the volume change of ancillary air chamber, thereby meeting actual demands of drivers.