Provided are a method for preparing an electrode system, an electrode system prepared therefrom, and an electric device including the same. The method includes the steps of forming a porous template having nanopores on a first electrode, wherein a diameter of the nanopores is between 5 to nm 500 nm; and forming a rod-type/tube-type second electrode inside the nanopores which are connected to the first electrode, the electrode system prepared therefrom, and an electric device including the same. With the large surface area, the electrode system of the present research improves efficiency and performance of various electric devices. The contrast and respond speed of the electrochromic device can be increased, and the number of electron-hole pairs of a solar cell is increased. The loss of electron-hole pairs is minimized, and charge storage of the supercapacitor and charge respond speed is heightened.