An electrical plug connector includes a metallic shell, and two conductive contact members. The two conductive contact members are respectively received in a top concave region and a bottom concave region of the insulated housing. When the electrical plug connector is inserted into a metallic shell of the electrical receptacle connector, each conductive contact members of the electrical plug connector comes in contact with the inner surface of the metallic shell of the electrical receptacle connector and a low-impedance grounding path is established between the metallic shell of the electrical plug connector and the metallic shell of the mating electrical receptacle connector through each conductive contact member.