A communication device, including a device casing, an external connection element, and a first metal element, is provided. A ground element and an antenna element are disposed in the device casing. The ground element has a first edge, a second edge, and a first connection point. The first edge and the second edge are opposite to each other. The first connection point is disposed near or at the second edge. The antenna element is disposed near the first edge. The external connection element is formed by a non-conductive material and is outside the device casing. The external connection element has a belt-like structure and is combined with the device casing to substantially form a loop structure. The first metal element is supported by the external connection element and is coupled to the first connection point of the ground element.