Methyl acrylate (MA) monomer was grafted onto ultra-high molecular weight polyethylene (UHMWPE) fibers after irradiation by γ-rays. The effects of absorption dose, monomer concentration and temperature on the degree of grafting (DG) were investigated. The grafting yield of MA reached to a considerable degree, approximately 151% at the maximum value. The DG of MA on UHMWPE fibers increased with the increment of absorption dose, temperature and concentration of MA. The function groups and morphologies of the UHMWPE fibers before and after graft polymerization were characterized by FT-IR and SEM.Cited