The grafting of 2,3-epoxypropylmethacrylate (GMA) on polypropylene (PP) fabric was carried out by the γ-ray preirradiation grafting technique. The grafting yield was found to be dependent on the storage condition of preirradiated samples. Also, it was found to increase with reaction temperature, and this means that reaction temperature is one of the important factors controlling the graft reaction. From Arrhenius plot, it was shown that the activation energy of the graft reaction was lower than those of other typical grafting polymerization. The total amount of trapped radical in polymer substrate was increased with decreasing of irradiation dose rate because irradiation time increase, but the real grafting yield was decreased due to the change of the partial trapped radical to peroxides.