A portable electronic device includes a main body, a motherboard, at least one connector, and at least one external graphics card module. The motherboard is disposed within the main body and equipped without a built-in graphics chip. The connector is disposed on the motherboard. The main body has at least one slot, and the slot is disposed at a position corresponding to the position of the connector. The external graphics card module includes a circuit board, and a graphic processing unit and a first connecting interface are electrically disposed on the circuit board. The external graphics card module is removable and selectively inserts into the slot, and the external graphics card module electrically connects to the motherboard via the first connecting interface.