A stacked receptacle connector includes an insulative housing forming a first receiving cavity extending along a front-to-back direction, a second receiving cavity stacked on the first receiving cavity along a vertical direction perpendicular to the front-to-back direction, and a mounting cavity located behind and communicating with the first and second receiving cavities. A printed circuit board (PCB) is mounted to the mounting cavity. A first connector having a front portion received in the first receiving cavity and a rear portion connected to the PCB. The first connector is fitted to be inserted by a first plug connector along two opposite direction. A plurality of contacts each has a mating portion received in the second receiving cavity and a mounting portion connected with the PCB. A plurality of footer pins connected the PCB to electrically connect the first connector and the contacts to an exterior substrate.