Herein, we proposed a facile electrodeposition method to prepare well-defined poly(3,4ethylenedioxythiophene)/graphene (PEDOT/GR) composite on the glassy carbon electrode (GCE) for the determination of nitrite as an electrochemical sensor. Scanning electron microscopy (SEM), UVvis spectroscopy (UV-vis) and electrochemical techniques were used for the characterization of the composite. It was found that PEDOT/GR composite was uniform, and formed a kind of encapsulated structures. Electrochemical experiments showed that this proposed PEDOT/GR composite-modified electrode exhibited excellent electrocatalytic properties for nitrite. Under the optimum conditions, the proposed sensor can be applied to the quantification of nitrite with a wide linear range covering from 0.3 to 600 μM and a low detection limit of 0.1 μM. Furthermore, the proposed sensor had good storage stability, reproducibility and anti-interference ability. To further validate its possible application, the method was successfully applied to the determination of nitrite in water samples.