An electrical connector includes an insulative housing defining a base portion and a mating tongue forwardly extending from the base portion, and a plurality of terminals insert molded in the housing. Each of the terminals defines a horizontal portion with a contacting section exposed upon the mating tongue, a tail portion bending out of the base portion, and a retaining section disposed between the horizontal portion and the tail portion and fully embedded within the base portion without exposure. The horizontal portion is provided in a rectangular shape, and at least a portion of the retaining section is provided in a round shape to provide good waterproof function with lower cost.