The method of irradiation grafting of DMAA onto AFLAS (alternating copolymer of tetrafluoroethylene and propylene) films was studied. The effect of the solvent on the grafting yield was determined. As a result, it might be important to evaluate the blood compatibility of the films already grafted by using an in vitro test. Benzene tests seem to be the most adequate for copolymerization. Grafting yield was better in the monomer 40-60% concentration range. The degree of grafting increases proportionally to dose rate in gamma ray radiation. The graft copolymerization is terminated via unimolecular mechanism.