Electrochemical oxidation of D(+)-glucose by a Pt/WO3 electrode in sulphuric acid medium was investigated by HPLC and in-situ FTIR spectroscopy. The oxidation on Pt/WO3 electrode was found to be a multi-step and multi-electron process. The major oxidation products were identified to be glucono-delta-lactone, CO2 and a probable five-member ring lactone. Based on these observations, the mechanism of glucose oxidation on Pt/WO3 was discussed.