This study reports a simple and effective method to make carbon felt surface hydrophilic and positively-charged by means of cetyltrimethylammonium bromide (CTAB) soaking. X-ray photoelectron spectroscopy and cyclic voltammetry indicated that CTAB could form a surfactant layer on carbon felt surface with the polar heads exposing outwardly. In an acetate-fed bioanode, the start-up time of current production and the time to reach stable current output at the CTAB-treated felt anodes were 36.1% and 49.4% shorter than the untreated anodes, respectively. Moreover, the maximum current output with these treated electrodes was 23.8% higher than the untreated counterparts. These results indicate that the CTAB treatment of carbon felt accelerates the anodic biofilm formation and enhances current output of BESs.