A cooling system for a vehicle includes a cooling apparatus including a radiator and a first water pump connected by a coolant line and circulating a coolant to the coolant line, a battery module provided on a battery coolant line selectively connected to the coolant line through a first valve, and a first chiller provided on the battery coolant line between the first valve and the battery coolant line. The first chiller is connected to a refrigerant line of the air-conditioning apparatus and is configured to heat-exchange the selective inflowed coolant with the refrigerant supplied from the air-conditioning apparatus to adjust a temperature of the coolant. The cooling system further includes an automatic driving controller connected to the coolant line so that the coolant is circulated inside, wherein the battery module or the automatic driving controller is cooled selectively by at least one cooling mode.