An electrical connector, for mating a mating connector having two metal elastic sheets, includes: an insulation body having a base portion and a tongue located at a front end thereof; an upper and lower rows of terminals fixed to the base portion, each terminal having a contact portion exposed from an upper or lower surface of the tongue; a middle shielding sheet, fixed to the base portion and tongue, and located between the two terminal rows; two snap-fit portions disposed at two sides of the middle shielding sheet and exposed from two sides of the tongue, where the two metal elastic sheets buckle the snap-fit portions to prevent disengagement; and an outer metal casing wrapping peripheries of the base portion and tongue. When the mating connector is inserted into the electrical connector after it's assembling, the two snap-fit portions are fixed to the mating connector to ensure stable high-frequency performance.