The redox behaviors of copper species at electrochemically activated glassy carbon electrodes have been investigated in aqueous solutions containing chloride anions. Experimental results showed that the voltammetric responses of copper species were influenced by the electrochemical activation means employed. Abnormal copper stripping was observed at electrodes obtained by cyclic polarization. Cyclic polarization would cause changes in the interwoven graphitic crystalline surface of glassy carbon, producing electrode interface with low distribution density of electron transfer sites for the early nucleation of metallic copper in the presence of chloride anion. Potentiostatic activation would generate oxygen-containing functionalities and maintain the basic surface structure of graphitic crystalline with high distribution density of electron transfer sites. (C) 2007 Elsevier Ltd. All rights reserved.