An electrical connector has an insulating housing defining a front wall. The front wall has a mating portion defining a plurality of passageways extending frontward and rearward in a top surface and a bottom surface respectively. A first terminal module has a plurality of first conductive terminals and a first base for restraining the first conductive terminals. The first conductive terminals have contacting portions extended outside the first base and arranged side by side to form one row for being received in the passageways defined in the top surface. A second terminal module disposed under the first terminal module has a plurality of second conductive terminals and a second base for restraining the second conductive terminals. The second conductive terminals have contacting portions extended outside the second base and arranged side by side to form one row for being received in the passageways defined in the bottom surface.