A liquid circulation system which is mounted on a droplet ejection device, comprising: a droplet ejection head formed with a common flow passage communicated with a plurality of nozzles for ejecting the droplets therefrom; a liquid filling container configured to be filled with liquid to be supplied to the droplet ejection head; a first flow passage for supplying therethrough the liquid from the liquid filling container to one end part of the common flow passage; a second flow passage for returning therethrough the liquid from an other end part of the common flow passage to the liquid filling container; a differential pressure generating means structured to pressurize the liquid on one end part side in the common flow passage and depressurize the liquid on an other end part side in the common flow passage; a pressurization regulator configured to be disposed between the differential pressure generating means and the one end part of the common flow passage and structured to maintain the liquid at the one end part in the common flow passage at a first pressure value; and a differential pressure regulator configured to be disposed between the differential pressure generating means and the other end part of the common flow passage and structured to maintain a differential pressure between both end parts in the common flow passage at a second pressure value, characterized in that the differential pressure regulator is configured to shut off flow of the liquid when a pressure value obtained by subtracting a pressure of the liquid of the other end part of the common flow passage from a pressure of the liquid of the one end part of the common flow passage becomes higher than the second pressure value, and the differential pressure regulator is configured to flow the liquid when the pressure obtained by subtracting the pressure of the liquid of the other end part of the common flow passage from the pressure of the liquid of the one end part of the common flow passage becomes lower than the second pressure value. a droplet ejection head formed with a common flow passage communicated with a plurality of nozzles for ejecting the droplets therefrom; a liquid filling container configured to be filled with liquid to be supplied to the droplet ejection head; a first flow passage for supplying therethrough the liquid from the liquid filling container to one end part of the common flow passage; a second flow passage for returning therethrough the liquid from an other end part of the common flow passage to the liquid filling container; a differential pressure generating means structured to pressurize the liquid on one end part side in the common flow passage and depressurize the liquid on an other end part side in the common flow passage; a pressurization regulator configured to be disposed between the differential pressure generating means and the one end part of the common flow passage and structured to maintain the liquid at the one end part in the common flow passage at a first pressure value; and a differential pressure regulator configured to be disposed between the differential pressure generating means and the other end part of the common flow passage and structured to maintain a differential pressure between both end parts in the common flow passage at a second pressure value, characterized in that the differential pressure regulator is configured to shut off flow of the liquid when a pressure value obtained by subtracting a pressure of the liquid of the other end part of the common flow passage from a pressure of the liquid of the one end part of the common flow passage becomes higher than the second pressure value, and the differential pressure regulator is configured to flow the liquid when the pressure obtained by subtracting the pressure of the liquid of the other end part of the common flow passage from the pressure of the liquid of the one end part of the common flow passage becomes lower than the second pressure value.