Disclosed herein is a cooling system for vehicle battery packs, including a double filter device mounted at an air inlet part, through which air for cooling the battery pack is introduced from the outside and/or the inside of the vehicle. The double filter includes a pre-filter having relatively large air holes, the pre-filter having high frequency of replacement, and a medium filter having relatively small air holes, the medium filter having low frequency of replacement. The pre-filter is located before the medium filter in the direction in which the air is introduced. Consequently, dust is removed from air, and therefore, the cooling efficiency of the battery pack is increased. In a preferred structure, metal dust is also effectively removed by the magnetic force applied to the medium filter. Consequently, the malfunction or short circuits of the battery pack are prevented. Also, air surrounding the battery pack is directly introduced through the through-type intake ports without passing through any pipe-shaped intake duct. Consequently, generation of noise, which is a problem caused when air in the cabin is used, and backward flow of flames and toxic gas, which are generated during a fire, are prevented. Furthermore, the battery pack is constructed in a compact structure.