A diamond film was deposited on silicon substrate using hot filament chemical vapor deposition (HFCVD), and H-2 and O-2 gases were added to the deposition process for comparison. This work evaluates how adding H-2 and O-2 affects the corrosion and wear-corrosion resistance characteristics of diamond films deposited on silicon substrate. The type of atomic bonding, structure, and surface morphologies of various diamond films were analyzed by Raman spectrometry, X-ray diffraction (XRD) and atomic force microscopy (AFM). Additionally, the mechanical characteristics of diamond films were studied using a precision nano-indentation test instrument. The corrosion and wear-corrosion resistance of diamond films were studied in 1 M H2SO4 + 1 M NaCl solution by electrochemical polarization. The experimental results show that the diamond film with added H-2 had a denser surface and a more obvious diamond phase with sp(3) bonding than the as-deposited HFCVD diamond film, effectively increasing the hardness, improving the surface structure and thereby improving corrosion and wear-corrosion resistance properties. However, the diamond film with added O-2 had more sp(2) and fewer sp(3) bonds than the as-deposited HFCVD diamond film, corresponding to reduced corrosion and wear-corrosion resistance. (C) 2008 Elsevier B.V. All rights reserved.