The electrical connector includes an insulative housing having a columnar section and an annular groove surrounding the columnar section. The column section includes a mating face and a plurality of power contact passageways and a plurality of signal contact passageways extending through the mating face wherein the signal contacts and the power contacts are commonly arranged with a cross configuration area to have the signal contacts located by opposite upper and lower sides of the power contacts. Both the power contacts and the signal contacts of the plug connector are of a blade type while both the power contacts and the signal contacts of the receptacle connector are of a clamp type wherein each signal contact has one clamping structure while each power contact has a pair of clamping structures side by side arranged with each other.