A novel electroactive star-shaped rod-coil copolymer composed of a benzene core and three symmetrically positioned tetraaniline-b-poly(ethylene glycol) arms, (TAni-b-PEG)(3) rod-coil block copolymer, is synthesized successfully and characterized using Fourier transform infrared spectroscopy (FTIR), UV-vis, H-1 NMR, and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. Uniform and high-quality (TAni-b-PEG)(3) thin films onto indium tin oxide-coated glass surface are fabricated simply from its DMF solution. Resulting (TAni-b-PEG)(3) copolymer thin films possess excellent electrochromic properties with a high optical contrast of 73.3%, superb coloration efficiency of 318.5 cm(2) C-1 at 750 nm. Very short switching times, that is, 2.11 s and 2.14 s for coloring and bleaching times, respectively, are observed as well. The mechanism of these impressive electrochromic properties of (TAni-b-PEG)(3) thin films possessed is proposed based on the atomic force microscopy investigation, star-shaped molecular geometry, synergetic electronic and ionic conductivity and amphiphilic self-assembly feature of (TAni-b-PEG)(3) copolymer, which can self-assemble to form cylinder pattern consisting of quick pathways for electronic charges and ionic species, respectively.