An electrical connector assembly comprises an insulative housing, a center pin having a first end protruding out of the insulative housing and a second end disposed in the insulative housing, a metallic sleeve enclosing the center pin for forming a receiving room therein and a protection member. The center pin is configured as a hollow structure and defines a center space therein with an opening at the second end thereof. The metallic sleeve comprises a solder portion disposed in the insulative housing. The protection member completely blocks the opening of the center pin.