A multi-band antenna used in a portable electrical device can operate in WWAN. The multi-band antenna includes a PCB, a first antenna body, and a second antenna body. The PCB has a first surface and an opposite second surface and defines a through hole extending from the first surface to the second surface. The first antenna body is formed on the first surface of the PCB comprising a first radiating element and a first grounding element. The second antenna body is formed on the second surface of the PCB. The second antenna body comprises a second radiating element, a second grounding element, and a connecting element connecting the second radiating element and the second grounding element. The first radiating element and the second radiating element electrically connect with each other via the through hole of the PCB. A feeding line has an inner conductor electrically connecting to the first radiating element and an outer conductor electrically connecting to the first grounding element.