The carbon fibrous mats (CFMs) formed by carbon nanofibers whose average diameter is about 150nm have been fabricated by thermally treating the electrospun polyacrylonitrile fibrous mats. The electrocatalytic activity of commercial Pt/C supported on the CFMs for methanol oxidation in a sulfuric acid solution has been investigated by cyclic voltammetry, chronoamperometry, quasi-steady state polarization, and electrochemical impedance spectroscopy (EIS) methods. The results show that the commercial Pt/C supported on the CFMs exhibits higher electrocatalytic activity, more stability, larger exchange current and smaller charge transfer resistance than that on commercial carbon papers (CPs), which reveals that the CFMs could be developed as suitably-supporting materials for Pt/C catalyst due to their special porous and continuous fibrous structures.