Polyaniline (PANI) and poly(o-toluidine) (POT) with various film thickness were electro-polymerized using potentiostatic method at the surface of GC electrode. The two conducting polymers were characterized by CV, in situ UV-vis spectroscopy and electrochemical impedance spectroscopy. Two composite catalysts (Pt/PANI/GC and Pt/POT/GC) with various film growth charge have been fabricated by the electro deposition of Pt on the PANI/GC and POT/GC at -0.1 V. then they were used for the electrooxidation of methanol in 0.5 M H2SO4 containing 1.0 M methanol. The properties of both the polymers change with the increase of film growth charge. As-formed composite catalysts were characterized by SEM and the electrochemical methods. The Pt nanoparticles deposited at -0.1 V exhibit thorns morphology and good dispersion on the POT with the film growth charge of 4.5 mC. The electrocatalytic activity for methanol oxidation of Pt/POT/GC is higher than Pt/PANI/GC for all the film charge, and they both exhibit the largest electrocatalytic activity at film charge of 4.5 mC. The present study shows that Pt/POT/GC would be a promising choice for methanol electrooxidation in comparison with Pt/PANI/GC. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.