Diamond-like carbon (DLC) thin films used in this study were intended for their electrochemical properties. The DLC films were deposited by a filtered cathodic vacuum arc (FCVA) process on p-type silicon (100) substrates biased at different pulse voltages (0-2000 V). The chemical bonding structures of the DLC films were characterized with micro-Raman spectroscopy and the electrochemical properties were evaluated by means of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The DLC films showed high impedance, high polarization resistance and high breakdown potential in a 0.5 M H2SO4 aqueous solution, which were attributed to the high SP3 content and uniformity of the films. The excellent chemical inertness of the DLC films made them promising corrosion resistant coating materials. (C) 2007 Elsevier B.V. All rights reserved.