Amorphous-carbon (a-C) films were deposited on a single-crystal silicon substrate by vacuum vapor deposition system and these amorphous carbon films were implanted with 110 keV C+ at fluences of 1 x 10(17) ions/cm(2). The effect of ion mixing on the surface morphology, friction behavior and adhesion strengths of amorphous carbon films was examined making use of atomic force microscopy (AFM), ball-on-disk reciprocating friction tester, nano-indentation system and scanning electron microscope (SEM). The changes in chemical composition and structure were investigated by using X-ray photoelectron spectroscopy (XPS). The results show that the anti-wear life and adhesion of amorphous carbon films on the Si substrates were significantly increased by C ion implantation. The Si-C chemical bonding across the interface plays a key role in the increase of adhesion strength and the anti-wear life of amorphous carbon film. The friction and wear mechanisms of amorphous carbon film under dry friction condition were also discussed. (c) 2005 Elsevier B.V All rights reserved.