A mating connector includes a plastic body, which has a main body and an insertion portion formed by extending forward from the main body. A mating space is concavely formed backward from a front end surface of the insertion portion. The insertion portion has a side wall located at a periphery of the mating space and running through the mating space to form at least two through-holes, and the two through-holes do not communicate with each other. A metal cover surrounds the plastic body and is fastened to the main body. A grounding sheet is located between the metal cover and the side wall. The grounding sheet has a body and at least two elastic portions formed by bending forward from the body. The body covers the side wall, and each of the elastic portions is accommodated in a corresponding through-hole and enters the mating space.