An dual-band antenna (100) used in a portable electronic device includes a first antenna unit (10) configured for receiving and/or sending wireless signals in low frequency bands, a second antenna unit (20) configured for receiving and/or sending wireless signals in high frequency bands; a feed unit (30) and a grounding unit (40). The first antenna unit, the second antenna unit and the feed unit are all connected to the grounding unit. A portion of the first antenna unit is positioned between the second antenna unit and the grounding unit. The first antenna unit and the second antenna unit are respectively positioned in different parallel planes.