Four chelating resins containing triethylenetetramine side chains and/or thiol groups were made from macroreticular 2,3-epithiopropyl methacrylate, styrene-divinylbenzene (DVB), or methyl methacrylate-DVB copolymer beads, and then the resins bearing metal ions such as Ag+, Cu2+, and Zn2+ were made. The antibacterial activity of the resins bearing metal ions against Escherichia coli (E. coli) or Staphylococcus aureus (S. aureus) was investigated. The resins containing thiol groups showed the higher adsorption capacity for silver ions than for other metal ions. The resins, which contain both triethylenetetramine side chains and thiol groups, bearing silver ions (RE-TTA-Ag) exhibited high antibacterial activity against bacteria, especially E. coli, without the residual silver ions in water after contacting with bacteria. The activity of the RE-TTA-Ag did not decrease even after reusing several times.