A wearable electronic device includes a ring-shaped main body, plural receiving parts, plural circuit boards and a wiring board. The plural receiving parts are disposed within the ring-shaped main body. The plural circuit boards are disposed within the corresponding receiving parts. One of the plural circuit boards corresponds to one receiving part. The wiring board is 111 within the ring-shaped main body and electrically connected with the plural circuit boards. Consequently, the circuit boards are electrically connected with each other through the wiring board.