A modular jack comprises a dielectric frame, a daughter board having a RJ45 connector and a transformer mounted thereon, a stacked USB connector, and first and second shields enclosing the frame and the daughter board. The daughter board provides a grounding pad on a surface thereof on which the RJ45 connector is mounted. The stacked USB connector has a grounding shell mounted on a rear portion thereof. The stacked USB connector and the RJ45 connector together with the daughter board and the transformer are secured in the frame with the grounding pad of the daughter board electrically connected with the grounding shell of the stacked USB connector.