A communication device. The communication device comprises a body, a battery unit and an ejecting device. The body comprises an opening, a first port, a first positioning portion and a receptacle. The opening is formed on one end of the body, and the receptacle is a hollow rectangular space connecting the opening and the body. The first port is an electrical contact disposed in the body connected to a circuit board installed therein. The first positioning portion is a recess or hole formed on the sidewall of the receptacle near the opening.