In order to obtain required polymer materials, acrylic acid was grafted onto powdered isotactic polypropylene by an electron beam preirradiation technique. All processes (including irradiation, storage of the samples, and grafting polymerization) were carried out in air. The effects of irradiation dose, storage time, reaction temperature, moth＇s salt, acid, and monomer concentration were investigated and discussed in detail. The results show that the grafting can be achieved well without purging oxygen, and moth＇s salt is indispensable for initiating grafting reaction and decreasing the homopolymerization. Optimal reaction conditions can be generalized for large-scale production of the desired polymer materials.