An electrical connector includes an insulative housing defining a mating slot, an inner metallic shield covering the insulative housing, and an outer metallic shield enclosing the insulative housing. The insulative housing includes a first wall, a second wall and two side walls. The inner metallic shield includes a main plate attached to the first wall and two side portions attached to the two side walls. The outer metallic shield includes a main plate located on the outer side of the main plate and two plates attached to the side portions respectively. The insulative housing is provided with grooves on the second walls. The plate is provided with a hook portion fixed in the groove. The two side portions engage the two plates.