We theoretically analyzed the surface structure of Au in alkaline solution and the glucose oxidation reaction to understand the electrooxidation process in direct alkaline glucose fuel cell. We find the oxidation reaction mechanism of glucose on Au catalyst in alkaline solution theoretically as follows. i) Glucose adsorbs on OH of Au surface. ii) OH- in alkaline solution interacts with CHO group of glucose. iii) Water is formed by proton transfer from CHO group of glucose to OH- in solution. iv) Gluconic acid is formed by OH transfer from Au surface. (C) 2013 Elsevier B.V. All rights reserved.