A cooling system includes a fixing device and a fan. The fixing device includes a fixing rack and a latching rack. The fixing rack includes a first latching arm and two opposite supporting arms protruding from two ends of the first latching arm. The latching rack includes a second latching arm and two opposite adjusting arms protruding from two ends of the second latching arm. The adjusting arms can be adjustably fixed to the supporting arms at different positions to adjust a distance between the first latching arms and the second latching arm to releasably fix the fan between the first latching arm and the second latching arm.