A heat exchange system employed to gasify liquid natural gas (LNG) or for other required purpose includes the cold substance such as LNG, a heat dissipation apparatus, a water storage tank, a heating portion, and a cooling portion. The heating portion is coupled between the cold substance and the water storage tank. The cooling portion is coupled between the heat dissipation apparatus and the water storage tank. The cooling portion transmits heat of the heat dissipation apparatus to water of the water storage tank to cool the heating portion, and the heating portion transmits heat of the water of the water storage tank to the cold substance.