An electrical connector includes an insulation base, a plurality of grounding terminals mounted in the insulation base and a plurality of differential signal terminal pairs mounted in the insulation base. The plurality of grounding terminals and the plurality of differential signal terminal pairs are arranged into a plurality of terminal rows. Each of the plurality of differential signal terminal pairs is located between two adjacent grounding terminals in one terminal row and between two other grounding terminals of two terminal rows adjacent to the one terminal row. The insulation base is provided with an electrical connection layer by which at least two of the plurality of grounding terminals are electrically connected to each other.