According to one embodiment of the present invention, a card edge connector (100) includes an elongated insulative housing (1) having a central slot (15) cooperatively enclosed by a bottom wall (150) and a pair of sidewalls thereof (13). A number of conductive terminals (2) are arranged along the central slot for mechanical and electrical engagement with a daughter circuit board (5) coupled thereto. The bottom wall of the housing defines a number of airways (151) in communication with the central slot, so as to dissipate heat generated by the conductive terminals during signal transmission to the outer circumstance timely.