The reactivity of 1-propanol, 1,3-propanediol, 1,2-propanediol and glycerol in electrocatalytic oxidation on Au, Pt and Pt-modified Au electrodes in alkaline solution has been investigated. Pt-modified Au electrodes have been prepared by depositing platinum on Au polycrystalline electrodes by the linear sweep voltammetric method. The oxidation of C3 alcohols on an individual electrode shows only a little difference in peak potential but a significant difference in peak current, and peak current is determined by the number and position of hydroxyl groups in the molecular chain. The oxidation of an individual C3 alcohol on Au and Pt electrodes shows the advantages of the Au electrode in peak current and of the Pt electrode in oxidation potential. Pt modification significantly improves the catalytic activity of Au electrodes. The catalytic activity shown by Pt-modified Au electrodes reflects the advantages of both Pt and Au electrodes.