In this work, the effect of immersion in silver nitrate solution on activated carbon fibers (ACFs) was investigated in relation to adsorption behavior and antibacterial activity of ACFs supported with silver (ACF/Ag). The pore and surface properties were studied in terms of BET volumetric measurement with nitrogen adsorption, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The antibacterial activities of ACF/Ag were studied in broth dilution tests against Staphylococcus aureus (S. aureus) and Escherichia coli (E. colt) from a point of view of water purification. As an experimental result, the silver content of ACF/Ag increased with increasing concentration of silver nitrate. It was found that the micropore structure slightly decreased as the silver nitrate concentration increased. Otherwise, it was revealed that the ACF/Ag possessed a strong antibacterial activity and an inhibitory effect for the growing of E. coli and S. auretts, respectively. Silver content on ACF/Ag decreased rapidly because of rough morphology of silver particles in water erosion. (C) 2003 Elsevier Science (USA). All rights reserved.