The electrochemical reduction Of CO2 has been investigated at the lowest possible overpotential value of -0.4 V (SCE) on polyaniline (PAn) electrodes under ambient conditions and under high pressure in the methanol + LiClO4 electrolyte system. When the applied pressure is increased, the current densities increase gradually. The main products are formaldehyde, formic acid and acetic acid. The maximum percent faradaic efficiencies of the products are found to be 26.5, 13.1 and 57.0% for HCHO, HCOOH and CH3COOH, respectively.