An electrical connector includes an insulating housing, an upper terminal assembly fastened in the insulating housing, a center grounding plate fastened in the insulating housing, and an outer shell disposed to a top surface of the insulating housing. A rear end of the insulating housing has two first penetrating grooves. The upper terminal assembly includes an upper base portion. A rear end of the upper base portion defines two second penetrating grooves. The two second penetrating grooves are aligned with the two first penetrating grooves. Two opposite sides of a rear end of a top surface of the outer shell extend towards the insulating housing to form two elastic arms, respectively. The two elastic arms pass through the two first penetrating grooves and the two second penetrating grooves, and then the two elastic arms contact with two outermost upper grounding terminals of the upper terminal assembly.