An antenna structure includes a ground element, a feeding radiation element, a first radiation element, a second radiation element, a third radiation element, a first capacitor, and a second capacitor. The ground element has a notch region. The feeding radiation element has a feeding point. The first radiation element is coupled to the ground element. The first capacitor is coupled between the feeding radiation element and the first radiation element. The second radiation element is coupled to the ground element. The second capacitor is coupled between the first radiation element and the second radiation element. The third radiation element is coupled to the feeding radiation element. The feeding radiation element, the first radiation element, the second radiation element, the third radiation element, the first capacitor, and the second capacitor are all disposed inside the notch region of the ground element.