The electroreduction of Cu(II) by polypyrrole (ppy)-modified electrode and stainless steel (SS) electrode under potentiostatic and potentiodynamic conditions was studied. Compared with SS electrode, ppy-modified electrode presented higher Cu(II) removal ability since it acted as electrocatalyst during reduction process. Extremely high current efficiency was achieved on ppy-modified electrode due to the inhibition effect on the side-reaction of hydrogen evolution, exhibiting important advantage over other electrode materials for heavy metal treatment. Conductivities of ppy films after different treatments were detected to evaluate the stability of the polymer.