The electrochromic (EC) response characteristics of EC-dye-modified porous electrodes composed of degenerate transparent conductive oxides were investigated. Although the In2O3:Sn and SnO2:Sb porous electrodes exhibited low electrical resistivity, the SnO2:Sb porous electrode exhibited a response slower than that of a conventional high-resistivity TiO2 porous electrode, whereas the In2O3: Sn porous electrode exhibited a faster response. Structural comparisons revealed that the pore size of the film consisting of small nanoparticles is one of the key factors controlling the EC response speed.