An electronic device includes a housing, a circuit board accommodated in the housing, a number of I/O ports mounted on the circuit board, and a port shield secured to the housing. The housing defines a number of openings, and the I/O ports are exposed from the plurality of openings. The port shield defines a number of receiving spaces to receive and position the I/O ports, thereby preventing the plurality of I/O ports from becoming loose and detaching from the circuit board.