An electrical connector (100) has a first end for fitting with another connector and a second end for connecting to a board. The connector comprises an insulative housing (1), a number of contacts (2) and a metal shield (3) enclosing the insulative housing. The insulative housing includes a tongue plate (11) with a number of passageways (110) defined therein for receiving the contacts. The contacts are arranged side by side in the first end and arranged in three parallel rows in the second end. The contacts include signal contact pairs (21) and grounding contacts (22) disposed adjacent to and separating the signal contact pairs. Each signal contact pair includes a first signal contact and a second signal contact being substantially in equal length of the first signal contact. The signal contact pairs have matched impedance for transmitting high-speed signals, thereby canceling any cross talk therebetween.