A cooling system may include an intercooler configured to heat-exchange a coolant and air, a radiator configured to cool a coolant heated in an engine through heat-exchange with air, a low temperature radiator configured to cool the coolant of the intercooler, a thermostat selectively fluid-connected to the radiator or the intercooler to supply the coolant from the radiator or the intercooler to the engine, a first control valve configured to selectively supply the coolant which has passed through the intercooler to the radiator, a second control valve configured to selectively supply the coolant which has passed through the engine to the intercooler or the first control valve, and a controller configured to control operations of the thermostat, the first control valve, and the second control valve according to a temperature of the coolant of the engine and a temperature of intake air.