A three dimensional（3D） porous conducting PEDOT nanocomposite doped with gold nanoparticles（AuNPs） was fabricated by polymerizing 3,4 ethylenedioxythiophene（EDOT）monomers and gold nanoparticles on a template of 3D arrayed polystyrene（PS）nanospheres,then removing the PS template.The nanostructure of prepared 3D porous AuNPs/PEDOT exhibited an excellent electrocatalytic property toward the oxidation of nitrite owing to its unique microstructure,where the doped AuNPs provided many active sites for the oxidation of nitrite,and the 3D porous structure facilitated the diffusion of nitrite molecules and accelerated the electron transfer.Based on this,the modified electrode was used in the detection of nitrite with a detection limit of 70 nmol/L and a wide linear range of 02-2 200 μmol/L.With the advantages of excellent selectivity,long term stability and good reproducibility,this sensor was applied in detection of nitrite in practical samples,and the results were consistent with those obtained by the standard method.