The present invention relates to a height-adjusting vehicle suspension using a fluid, the suspension comprising: a height-adjusting cylinder which is provided on the lower portion of a vehicle body, has a piston and a piston rod which are lifted by hydraulic pressure, and is halved into an upper cylinder and a lower cylinder by means of the piston; buffer pockets which are connected to the height-adjusting cylinder so as to absorb shock caused by the hydraulic pressure inside the height-adjusting cylinder; a pressure maintenance pocket which is connected to the height-adjusting cylinder so as to supply a fluid to the inside of the upper cylinder or the lower cylinder; a pumping device which supplies the fluid to the pressure maintenance pocket so as to enable the pressure inside the pressure maintenance pocket to be maintained at a level that is within a predetermined high pressure range; and a return pocket which communicates with the height-adjusting cylinder and the pumping device so as to receive the fluid from the height-adjusting cylinder and supply the fluid to the pumping device. In addition, the height-adjusting cylinder receives the fluid from the pressure maintenance pocket, thereby lifting the piston and the piston rod and thus enabling the height of the vehicle body to be adjusted. In addition, according to the present invention, the effect is gained of being able to provide a suspension having quick response characteristics even when having a small-capacity pumping device, by means of a working fluid, such as air or the fluid, flowing rapidly by means of a pressure difference among the pockets, which each comprise an outer tube formed from a metal material and an inner tube having elastic force, the elastic force of the inner tubes, and the swift opening/closing of valves.