Abstract: An electrical connector includes an insulative housing, a number of conductive contacts affixed to the insulative housing, a middle shielding plate affixed to the insulative housing, a shielding shell enclosing the insulative housing for forming a mating room; and an outer metal shell enclosing the shielding shell. The insulative housing has a base portion and a tongue portion extending forwardly from the base portion. The electrical connector further includes a sealer with an o-ring at a front end thereof. The sealer is insert-molded with the shielding shell for forming a waterproof structure enclosing the insulative housing. A front end of the outer metal shell resists the sealer. The outer metal shell encloses the sealer, making the sealer attach to shielding shell firmly. The sealer achieves a good waterproof effect.