A seawater circulation system comprising: a sea chest for pumping seawater from sea; a cooling part coupled to the sea chest to receive the seawater from the sea chest, and coupled to a heat generation body to lower a temperature of the heat generation body through heat exchange; a scrubber part for processing an exhaust gas generated in a ship; a first discharge pipe part coupled to the cooling part to receive the seawater discharged from the cooling part; a supply pipe part having one end coupled to the cooling part or the first discharge pipe part and an opposite end coupled to the scrubber part, and configured to supply a part or all of the seawater, which is discharged from a pipe connected to the one end of the supply pipe part, to the scrubber part; a second discharge pipe part coupled to the scrubber part to receive the seawater discharged from the scrubber part; the cooling part includes a first pump for pumping the seawater from the sea chest, the supply pipe part includes a second pump for pumping the seawater from the cooling part or the first discharge pipe part, and the second pump is installed adjacent to the scrubber part, and configured to receive the seawater from the cooling part or the first discharge pipe part, to which the seawater pumped by the first pump is supplied, characterized in that the seawater circulation system comprises a stirring part coupled to the first discharge pipe part and the second discharge pipe part to receive and stir the seawater discharged from the first discharge pipe part and the second discharge pipe part, wherein a valve for adjusting a flow rate is provided between the cooling part or the first discharge pipe part and the supply pipe part, and that a ratio of a pumping flow rate of the second pump to a pumping flow rate of the first pump is set from 0.42 to 0.44. a sea chest for pumping seawater from sea; a cooling part coupled to the sea chest to receive the seawater from the sea chest, and coupled to a heat generation body to lower a temperature of the heat generation body through heat exchange; a scrubber part for processing an exhaust gas generated in a ship; a first discharge pipe part coupled to the cooling part to receive the seawater discharged from the cooling part; a supply pipe part having one end coupled to the cooling part or the first discharge pipe part and an opposite end coupled to the scrubber part, and configured to supply a part or all of the seawater, which is discharged from a pipe connected to the one end of the supply pipe part, to the scrubber part; a second discharge pipe part coupled to the scrubber part to receive the seawater discharged from the scrubber part; the cooling part includes a first pump for pumping the seawater from the sea chest, the supply pipe part includes a second pump for pumping the seawater from the cooling part or the first discharge pipe part, and the second pump is installed adjacent to the scrubber part, and configured to receive the seawater from the cooling part or the first discharge pipe part, to which the seawater pumped by the first pump is supplied, characterized in that the seawater circulation system comprises a stirring part coupled to the first discharge pipe part and the second discharge pipe part to receive and stir the seawater discharged from the first discharge pipe part and the second discharge pipe part, wherein a valve for adjusting a flow rate is provided between the cooling part or the first discharge pipe part and the supply pipe part, and that a ratio of a pumping flow rate of the second pump to a pumping flow rate of the first pump is set from 0.42 to 0.44.