Abstract: An air conditioning system of a vehicle and a control method thereof, includes a distance sensor that is configured to detect a distance from the vehicle to another vehicle in front of the vehicle; a humidity sensor that is configured to detect an inside humidity of the vehicle; an inside temperature sensor that is configured to detect an inside temperature of the vehicle; an outside temperature sensor that is configured to detect an outside temperature of the vehicle; and a controller electrically connected to the distance sensor, the humidity sensor, the inside temperature sensor, and the outside temperature sensor and configured for determining an air conditioning mode of the vehicle based on the distance to another vehicle in front detected by the distance sensor, the inside humidity of the vehicle detected by the humidity sensor, the inside temperature of the vehicle detected by the inside temperature sensor, and the outside temperature of the vehicle detected by the outside temperature sensor.