The invention discloses an electronic apparatus and a heat radiation substrate thereof. The electronic apparatus comprises laminated PCB (printed circuit board) and the heat radiation substrate. Part of the PCB region is provided with a heat source, the heat radiation substrate at least comprises a first heat radiation region and a second heat radiation region which are connected with each other, the heat radiation property of the first heat radiation region is better than that of the second heat radiation region, the first heat radiation region corresponds to the heat source on the PCB and is larger than that of the heat source on the PCB. The invention can basically ensure the heat radiation effect and simultaneously and effectively reduce the cost.