The effects of 3 additives (sulfur,trimethylolpropane triacrylate (TMPTA)and petaerythritol tetraacrylate (PETA) on radiation cross — linking of LLDPE — EPDM are investigated in this paper. The gel percentage content,mechanical properties and heat age resistances of the blends with various compositions and radiation dosage have been studied. It can be concluded that all the 3 additives are helpful to the radiation cross—linking of LLDPE—EPDM blends and could approve its properties, but sulfur is the best. Based on the above,the blended materials with tensile strength and elongation above 20 MPa, 500% respectively have been made by LLDPE 100, EPDM 50 — 100,S 0.5 — 2 parts and other additives 30 — 40 parts. These materials also have the characteristics of excellent heat aging, weather resistance, low temperature flexibility and toughness. They can be used for the outer jacketing of wire or cable, pliability and strong heat shrinking products.