The present invention relates to a nanostructure having an electrochromic material attached to the surface thereof, and a preparation method therefor. To this end, the present invention provides: a nanostructure comprising a metal oxide and having a structure comprising nanopores; and an electrochromic structure comprising an electrochromic material to be attached to the surface of the nanostructure. According to the present invention, the nanostructure has a surface area larger than that of conventional nanoparticles so as to enable more electrochromic materials to be attached thereto, and thus the electrochromic characteristics of an electrochromic device can be improved.