A simple and reliable method was developed for the electrochemical determination of nitrite based on glassy carbon electrode(GCE) modified with Au nanoparticles(AuNPs)encapsulated in dendrimers．Firstly，chitosan(Chit) was modified on the GCE，and in the presence of coupling agent carbodiimide，carboxyl-terminated poly(amidoamine)(generation 4.5) dendrimers were covalently attached onto chitosan through the formation of amide bonds between carboxylic acid groups of the dendrimer and amine groups of chitosan．The Au(Ⅲ) ions were coordinated in the interior of dendrimer with nitrogen ligands and then reduced to form AuNPs，which was written as Den(AuNPs)/Chit/GC electrode．The Den(AuNPs)/Chit/GC electrodes were characterized with cyclic voltammetry(CV)，electrochemical impedance spectroscopy(EIS)．The experimental results showed that the present Den(AuNPs)/Chit/GC electrodes have excellent sensitivity for nitrite determination．The chronoamperometric studies revealed that the amperometric response was rapid and stable，and offered a linear dependence over the ranges of nitrite concentrations from 2 μmol/L to 20 μmol/L and 0.07 mmol/L to 1.12 mmol/L with a limit of detection(S/N=3) down to 1.0 μmol/L．The method was applied in the determination of nitrite in real sample with satisfactory result．Den(AuNPs)/Chit/GC electrodes are to provide a nanostructured platform for the development of electrochemical sensors and biosensors.