Electrochromic devices are reported by using polyaniline (PANI) doped with poly(styrene sulfonic acid) (PSS) as coloring electrodes, poly(ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) as complementary electrodes, and poly(methyl methacrylate)(PMMA)-based electrolyte as gel electrolyte. Characterizations of the PANI-PSS are performed using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and UV-vis spectroscopy (UV). The spectroelectrochemical and electrochromic properties of electrochromic devices are investigated, electrochromic device based on PMMA-based gel electrolyte shows larger coloration efficiency, larger optical contrast, and faster response time than that based on liquid electrolyte at long term cycles.