A multi-band antenna adapted to a portable electrical device capable of operating in various wireless communication bands includes a first radiating conductor having opposite elongated sides, a second radiating conductor extending from one end of the first radiating conductor, a third radiating conductor arranging about a central area of the first radiating. Both the second radiating conductor and the third radiating conductor extend from the same elongated side of the first radiating conductor. A feeding body is curved and extended from the third radiating conductor. According to a position that the feeding body connecting to the third radiating conductor and designed the feeding body, operation of the multi-band antenna has a preferred range of a low frequency bandwidth and a high frequency harmonic bandwidth.