A liquid circulation system includes an inkjet head formed with a common ink flow passage, an ink cartridge, a supply flow passage through which ink is supplied from the ink cartridge to an inlet of the common ink flow passage, a return flow passage through which the ink is returned from the outlet of the common ink flow passage to the ink cartridge, a tube pump sending the ink in the supply flow passage, a tube pump sending the ink in the return flow passage, a pressurization bellows unit pressurizing the ink in the supply flow passage, a pressure reduction bellows unit depressurizing the ink in the return flow passage, a pressurization regulator maintaining the inlet being a center value “+α” of a designated head value, and a differential pressure regulator by which a differential pressure of the ink between the inlet and the outlet is maintained to be “2α”.