A novel type of weakly acidic cation exchange fiber have been prepared by (CO)-C-60 irradiation grafting with acrylic acid onto the polytetrafluoroethylene (PTFE) fiber. The exchange capacity of the grafted fiber is 3.06 mmol/g. The pH titration curve of the grafted fiber showed there is a sudden jump when pH is round 6-10, and the acidity of the grafted fiber is stronger than that of commercial weakly acidic exchange D- 152 resin. The grafted fiber showed the excellent selectivity of static and dynamic adsorption for Cu2+, La3+ and Pb2+ when Mg2+, Ca2+, Cr3+, Co2+, Ni3+, Cu2+, Ag+, La3+, Ph2+ were coexisted. The grafted fiber could be regenerated completely with almost equimolar diluted hydrochloric acid. (c) 2005 Elsevier B.V. All rights reserved.