Two types of inorganic supports, MgCl₂, for the impregnation of catalysts were prepared the recrystallization and sol-gel methods, respectively. The Ziegler-Natta/Metallocene hybrid catalysts were prepared in order to control the molecular weight (Mw) and the molecular weight distribution (MWD) during ethylene polymerization. The polyethylene produced by the hybrid catalysts can control the Mw and the MWD of polymer, showing two melting temperatures and a bimodal MWD, corresponding arising from each of the individual catalysts. This suggests that these hybrid catalysts acted as individual active species and produced a blend of polymers.