A cyclic-amine monomer, 3-allyl-5,5-dimethylhydantoin (ADMH), was grafted onto various textile materials in a continuous finishing process to prepare durable and regenerable antibacterial textiles. Highly efficient radical grafting polymerizations occurred inside or on the surfaces of fibers with the assistance of different initiators. In the finishing process, particular factors such as types and concentrations of radical initiators, drying, and curing conditions were rather important in effecting the final grafts of ADMH on fabrics and were studied carefully. After exposure to chlorine, the grafted hydantoin structures in the samples could be transformed into N-halamines, which provided powerful, durable, and regenerable antibacterial activities. The influence of hydrophilic/hydrophobic properties of the fabrics on the antibacterial activities was discussed.