In this paper, several kinds of silver supporting activated carbon fibers (ACF-Ag) were prepared by the reduction adsorption on activated carbon fiber (ACF) activated with steam or H3PO4 using sisal, viscose and pitch fiber as precursors. Their pore structure and surface chemistry were characterized using nitrogen adsorption, XPS, WXRD and ICP quantitative analysis. Their antibacterial activities were tested. The results showed that metallic silver particle in micron or nano-scale size could be easily and dispersedly supported onto the surface of ACF using reduction property of ACF without largely decreasing their specific surface area. The ACF-Ag showed strong antibacterial activity against Escherichia coli and Staphylococcus aureus. The antibacterial activity has closed relationship with the precursors, the method of activation, silver content and the specific surface area of the ACFs. Generally, higher silver content and higher specific surface area provide the materials stronger antibacterial activity. ACF activated with phosphoric acid, due to the presence of certain amount of organic phosphoric groups on the surface, showed stronger antibacterial activity than those activated with steam. The antibacterial materials can be easily regenerated without decreasing their antibacterial activity and without releasing large amount of silver from the solid phase. (c) 2005 Springer Science + Business Media, Inc.