Ordered mesoporous carbon (OMC) was treated with HNO3 or NaOH. The two treated OMCs have many oxygen-containing functional groups. Those treated with HNO3 have more acidic surface groups than those treated with NaOH. Nicotinamide adenine dinucleoticle (NADH) and H2O2 were selected as marker molecules for the comparison of the electrocatalytic property of the OMCs. A comparison between the cyclic voltammograms shows that the oxidation peak potential of NADH is 0.614 V at a bare glassy carbon electrode (GCE), 0.205 V at OMC/GCE, 0.223 V at NaOH-treated OMC/GCE, and 0.0V at HNO3-treated OMC/GCE (vs.Ag/AgCl). The results indicate that the HNO3-treated OMC/GCE exhibits the highest electrocatalytic activity for NADH oxidation. Thus, acidic groups rather than other oxygen-containing functional groups, play a very important role in the catalytic activity of OMC. (C) 2010 Elsevier Ltd. All rights reserved.