A heat dissipating system includes a wind tunnel, a first electronic element, and a second electronic element. The wind tunnel defines a top air inlet channel and a separated bottom, and a top air discharging channel and a separated bottom air discharging channel. Air entering the bottom air inlet channel dissipates heat produced by the first electronic element to the top air discharging channel, to flow out of the wind tunnel. Air entering the top air inlet channel flows to the bottom air discharging channel to dissipate heat produced by the second electronic element, this arrangement avoids heated air from one element being exhausted onto another element.