An antenna device includes an insulating substrate, a ground plane, a radiating element, a horizontal polarized portion and a vertical polarized portion. The insulating substrate has a first surface and a second surface opposite to the first surface, one end of the first surface defines a first isolating area and a second isolating area, one end of the second surface adjacent to the first and second isolating areas defines an insulating area, a horizontal feed circuit and a vertical feed circuit are disposed at the insulating area. The ground plane includes a first ground plane and a second ground plane. The radiating element is positioned opposite to and spaced from the first ground plane. The horizontal and vertical polarized portions are positioned on the radiating element and corresponding to the first and second isolating areas respectively so as to couple with the horizontal and vertical feed circuits, respectively.