An electrical connector structure includes an insulating housing, a first terminal set, a second terminal set, a third terminal set and at least one conductive member. The first, second and third terminal sets are disposed in the insulating housing. Each of the first and second terminal sets includes a plurality of signal terminals and at least one ground terminal. The conductive member is electrically connected to the ground terminals of the first and second terminal sets, and is not electrically connected to the third terminal set.