A gold nanoparticles/poly o-phenylenediamine modified glod electrode(nano-Au/POPD/Au) was prepared by consecutive cyclic voltammetry(CV) and the performances of different modified electrodes were studied in alkaline solution.The results showed that the nano-Au/POPD/Au electrode was highly active and stable for electrooxidation of formaldehyde,and its electrocatalytic current at the potential of 0.3 V was 2.1 times higher than that of nano-Au/Au electrode.Effects of various parameters such as nano-Au loding(sweep cycle and scan rate)，scan rate,NaOH concentration on the electrocatalytic oxidation of formaldehyde were also investigated.Under the optimum conditions,the calibration curve of formaldehyde was linear in the concentration range of 0.1-600 mg/L.The detection limit(S/N=3) was 0.01 mg/L.The method was applied in the determination of formaldehyde in red wine and skiphop children plastic dish,and the results were in agreements with those obtained by the standard acetylacetone method.