The present invention relates to an ink recharging system in which the ink can be recharged into a used ink cartridge repeatedly, a bulk ink cartridge used in the system, and a method for recharging the ink into the ink cartridge using them. The ink recharging system for the ink cartridge installed in an inkjet printer comprises a compressor and a positive pressure tank for providing the compression force to supply the ink stored in the quantitative ink supply cylinder to the ink cartridge, a charging cylinder for applying the compression force and the suction force to the quantitative ink supply cylinder, automatic quantitative position control means for measuring the movement displacement of the charging cylinder, a vacuum pump and a negative pressure tank for producing a vacuum in the ink cartridge, and a compressed air supply tube diverged and connected to the inlet and outlet of the charging cylinder from the positive pressure tank via the solenoid valve for air pressure. The present invention provides a recharging system for the ink cartridge and a method for recharging the ink cartridge, in which the remaining air or ink in the recycled ink cartridge can be easily discharged and vacuum degree of the ink cartridge can be precisely controlled by the control means for the quantitative position, to thereby charge the quantitative ink into the recycled ink cartridge rapidly and accurately, and relates to a bulk ink cartridge which can prevent wrong installment with simple identifying members.