A single feed-in dual-band antenna structure includes a first radiation unit, a basal plate and a plurality of matching components. The basal plate includes a front side, a back side and an edge side. A first ground unit, a signal feed-in unit, a second radiation unit and an electrode part are arranged on the front side. A third radiation unit is arranged on the edge side. A second ground unit is arranged on the back side of the basal plate. The first radiation unit is electrically connected to the electrode part. The first radiation unit is adjusted to control the 2.45 GHZ frequency range impedance, resonant frequency, bandwidth and radiation effect. The third radiation unit frequency wave length controls the 5 GHZ frequency range to achieve the predetermined target impedance, resonant frequency, bandwidth and radiation efficiency. The antenna size can be reduced effectively.