In this paper, the electrochemical behavior of polypyrrole nanowire modified electrode is described. The modified electrode has very goodactivity toward nitrite electroreduction. The electroreduction current is linearly dependent on the concentration of nitrite. The experimentalparameters such as thickness of polypyrrole film, pH, and temperature of the test solution, and scan rate which have effects on the reductioncurrent were examined. The result shows that the electroreduction current increases with the increasing of the polypyrrole film thickness,acidity of electrolyte solution, temperature, and scan rate. The good linearity between the electroreduction current and the concentrationof nitrite makes it possible to determine nitrite concentration accurately in the range of 2.28 × 10−4 to 0.020 M.