Electrochromic devices (ECD) can change light transmission properties in response to voltage during electrochemical redox process. Although the colour of the conductive polymer like polyaniline (PANI) can be controlled electrically, but its performance is still considered to be low due to the lack of conducting pathways at the nanoscale associated with random deposition morphology. Thus improvement can be achieved by incorporating with nanofillers namely carbon nanotubes that have excellent electrical conductivity, high surface area and good interconnectivity. A new dispersion technique of CNTs and PANI has been done in order to get uniform PANI/CNT film. PANI/CNTs film with various CNTs loading were produced by electrochemical process on FTO substrate and were then characterized using Hall Effect measurement and UV-Vis spectroscopy. PANI/CNTs films were assembled into test cells for testing. It is found that the higher the CNTs loading during deposition, the higher the conductivity. In UV-Vis spectra, the sample with higher CNTs loading will get lower transmittance. In electrochromic testing, the test cell has response towards voltage applied and changed the colours from green to purple. The test cell has shows no sign of leakage, thus it has been improved. © 2012 American Institute of Physics.