In the present investigation, the role of the pore morphology of mesoporous carbons in the electrocatalytic activity of Pt nanoparticles for fuel cell reactions has been successfully revealed by adopting ordered mesoporous carbon CMK-3 and disordered wormhole-like mesoporous carbon (WMC) as the support material, respectively. Both materials possess very similar pore characteristics (pore volume, BET surface area, mesopore size) except pore morphology. It has been found that CMK-3 can provide Pt nanoparticles with more electrochemically active Pt sites and higher electrochemical surface area, and thus, Pt/CMK-3 exhibits superior fuel cell reactions activity compared to Pt/WMC, especially in the case of liquid reactants (e.g. ethanol). This could be attributed to the much easier mass transportation through CMK-3 support profiting from both the high ordered degree and the very good 3D interconnection of the nano-spacings of their hexagonally arrayed carbon nanorods (i.e. mesopores), thus leading to more accessibility of Pt nanoparticles. The above results demonstrates that the pore morphology of carbon supports plays a decisive role in the electrocatalytic activity of their supported Pt nanoparticles, although other structure parameters like pore size are very similar. (C) 2010 Elsevier B.V. All rights reserved.