A dual-band antenna includes a feed portion, a ground portion, a radiating portion and a fine-tuning portion. The feed portion is operable to feed electromagnetic signals. The radiating portion includes a first radiator, a second radiator and a connecting portion. The first radiator is elongated and has a first end electrically connected to the ground portion, and a second end of the first radiator is floating. The second radiator is U shaped, with two open ends floating. The connecting portion is connected to the first radiator, the second radiator and the feed portion. The feed portion feeds electromagnetic signal to the first radiator and the second radiator via the connecting portion. The fine-tuning portion is arranged around the second radiator, operable to control operating frequency bands of the second radiator.