Abstract: In situ electrochemical polymerization of an aniline solution containing multi-walled carbon nanotube (MWCNT) of 0.8 wt.% was used to prepare (MWCNT)/polyaniline(PANI) composite films. The electrochemical capacitance performances of these films were investigated with cyclic voltammetry (CV) and ac impedance spectroscopy in 1 M H2SO4 with a three-electrode system. It was found that the MWCNT/PANI films show much higher specific capacitance (SC), better cyclic stability and more promising for applications in supercapacitors than a pure PANI film electrode. The highest specific capacitance value of 500 F g−1 was obtained for the MWCNT/PANI composite film.