Disclosed is a hinge structure that includes a first shaft, a second shaft, a first arm part, a second arm part, a first rotation part, a second rotation part, a first main gear, a second main gear, and first and second compound gears disposed between the main gears. The first compound gear may include a first gear portion geared with the first main gear, and of which a distance from a center point to a gear tooth end is a first radius, and a second gear portion geared with the second compound gear, and of which a distance from a center point to a gear tooth end is a second radius that is smaller than the first radius. The second compound gear may have a structure corresponding to that of the first compound gear. An electronic device including the hinge structure is also disclosed.