The effect of electrode thickness and density for unpressed and pressed natural graphite electrodes were studied using electrochemical characterization. Pressing the graphite electrode decreased the reversible capacity and the irreversible capacity loss (ICL) during formation. As electrode density increased, the capacity retention at high rate increased until 0.9 g/cm(3), and then decreased. The cycle performances of the pressed graphite electrodes were more stable than the unpressed one. Pressing graphite electrode affected on its electrochemical characterization such as ICL, high rate cycling and cycle performance. (C) 2003 Published by Elsevier Science B.V.