Abstract: Surface contact disinfection technique is a newly developed method for water sterilization. In this process，the solid surface contact materials with antibacterial ability are used. The antibacterial performance will improve with the increase of antibacterial group on the surface of materials. A new type of antibacterial materials was prepared and designed to be used for surface contact disinfection process. The materials were prepared by grafting quaternary ammonium salts (QAS) onto cellulose fiber with direct irradiation grafting and pre-irradiation grafting methods. The factors，such as reaction time，temperature，monomer concentration，irradiation dose，which influenced the percentage of grafting in the grafting polymerization reactions，were studied and optimized. The modified cellulose fibers were characterized by FTIR and SEM. The results showed that the antibacterial cellulose fibers with a percentage of grafting above 55% were obtained by the pre-irradiation grafting method.