A cooling
system for vehicles and a control method thereof improves indoor heating performance and
fuel efficiency by controlling a flow rate of a
coolant passing through a
heater core together with an EGR cooler. A
coolant having an increased temperature is first supplied to the
heater core side through a flow stagnancy control to rapidly increase the temperature of the
coolant flowing in the
heater core, thereby improving heating performance. A warm-up feature is improved through an
exhaust heat recovery function by a heat exchange between the
exhaust gas and the coolant in the EGR cooler, thereby improving efficiency of fuel.