Cu 2 O on active carbon (Cu 2 O/AC) catalysts were prepared by impregnation of support with aqueous solutions of CuSO 4 in various concentrations and then treated with a mixture of glucose and NaOH. Photocatalytic activity of the prepared catalysts was investigated in the photocatalytic degradation of pyrocatechol. The catalyst prepared by dipping of 0.5 g of AC into 25 ml of 0.04 mol/l CuSO 4 was found to exhibit the best activity. The effects of the reaction time and the amount of catalyst on the photocatalytic degradation of pyrocatechol were also studied.