A multi-band antenna includes a base portion, a substantially lying U-shaped first radiating portion, a substantially lying L-shaped second radiating portion and a third radiating portion. A rear edge of the base portion extends rearward to form a ground portion with a ground point being defined thereon. A top of the base portion defines a feeding point. The first radiating portion of which one end is connected with a first side edge of the base portion and the mouth faces to the first side edge of the base portion. The second radiating portion is connected with a second side edge of the base portion. The third radiating portion tortuously extends downward from a front edge of the base portion, then extends transversely, and further circuitously extends rearward to be located substantially near under a free arm of the second radiating portion.