A heat dissipating system including a casing body, a heat source and a piezoelectric fan is provided. The casing body includes an upper casing and a bottom case, wherein at least one of the upper casing and the bottom casing includes at least one air inlet. The heat source and the piezoelectric fan are both disposed in the casing body. The piezoelectric fan has an opening facing the heat source while the air inlet is adjacent to the opening. Air is adsorbed into the opening through the air inlet and is exhausted out towards a direction of the heat source by the piezoelectric fan.