The effects of gaseous oxygen on the anodic behaviour of Vulcan XC-72 carbon electrode have been investigated in 96% $H_3PO_4$ at 145℃ by using potentiodynamic and potentiostatic methods, followed by FTIR spectroscopic study. From the results of potentiodynamic polarization experiments, the passive region could be clearly observed in the potential range of 600 to 800 $mV_{SCE}$ when gaseous oxygen was blowed to the other side of the electrode which contacts with solution. Potentiostatic current transients could be differentiated into three stages of anodic behaviour by the exponent n, based upon $i = ke^{-n}$ relationship between current and time. The exponent n decreased with increasing anodic potential and increased at a constant potential as gaseous oxygen was blowed to the electrode. The results of FTIR spectroscopy showed the amounts of surface oxides such as carboxyl and quinone were larger in the specimen blowed with gaseous oxygen than the specimen exposed to air under the applied potentials of 800 $mV_{SCE}$ and 1200 $mV_{SCE}$. From the above experimental results, it is suggested that the blow of gaseous oxygen promotes the formation of surface oxides on the carbon electrode.
