Electrocatalytic oxidation of glucose in alkaline and neutral solutions was examined using carbon electrodes modified with 2nm core sized gold nanoparticles (Au 2nm nanoparticle). The voltammetric responses for the electrocatalytic oxidation of glucose at Au 2nm nanoparticle-modified electrodes in both alkaline and neutral solutions were similar to those at a gold plate electrode. However, the different results were obtained for the electrolysis of glucose between Au 2nm nanoparticle-modified and gold plate electrodes. The current flow due to the oxidation of glucose during electrolysis at the gold plate electrode decreased quickly with time, due to the electrode surface poisoning. On the other hand, the decrease in current flow at the Au 2nm nanoparticle-modified electrode was much improved in both alkaline and neutral solutions.The electrolytic oxidation of glucose was performed at Au 2nm nanoparticle modified electrodes in both alkaline and neutral solutions. In the alkaline solution, at a potential of −0.3V, gluconolactone (or gluconate) was formed with a current efficiency of 100%, while at potentials of −0.1 to 0.3V, oxalate and gluconolactone (or gluconate) were obtained as main products. In a neutral solution, electrolysis at 0.1 and 0.3V, gluconolactone (or gluconate) was obtained with current efficiencies of 88–100%.