There is disclosed an ink cartridge including a cylindrical member having an ink port at one axial end thereof, a piston, a piston rod, and a thrusting portion. The piston rod is fitted in the cylindrical member air-tightly and slidably, and partially defines an ink chamber within the cylindrical member. The ink chamber is in communication with the ink port. The piston rod is connected to the piston on the side opposite to the ink chamber, and extends in the cylindrical member along an axial direction of the cylindrical member. The thrusting portion is at least partially positioned in the cylindrical member and configured to apply a thrust force to the piston rod and thereby move the piston along the axial direction. The thrusting portion comprises a driven portion drivable from the exterior of the cylindrical member.