An improved Universal Serial Bus (USB) connector apparatus is provided. In one embodiment, the USB connector apparatus comprises a top wall; a bottom wall having one or two openings; two side walls; an internal cavity with a rectangular cross section enclosed by the top wall, the bottom wall and the two side walls; a gasket disposed within the internal cavity; and a first connecting piece made of a conductive material and positioned at the one or more openings of the bottom wall and at least partially covering the one or more openings of the bottom wall, wherein the top wall, bottom wall, two side walls, internal cavity and gasket are configured to comply with a USB interface standard. The USB connector apparatus ensures that a bottom wall elastic sheet of the USB socket effectively contacts with the bottom wall of the USB connector, thereby providing higher grounding performance. Further, it improves on the conventional USB connector without much additional cost.