The spherical MgCl2 supports treated by methylaluminoxane (named MAO-supports) were prepared using MgCl(2)(.)2.56C(2)H(5)OH adducts as support material subjected to elimination of EtOH by thermal dealcoholization treatments. Then bis(phenoxy-imine) zirconium complex, bis-[N(3-tert-butylsalicylidence)cyclohexylaminato] zirconium(IV) dichloride (1), was directly impregnated onto these MAO-supports. ICP, EDX, GC, N-2-BET, IR and XRD analyses indicated that the texture of the supports and MAO-supports, the elements on solid catalysts, and so on, were greatly relied on dealcoholization temperature. Meanwhile, it was also found that the activities of the supported catalysts for ethylene polymerization and the properties of resultant polymers were strongly dependent on dealcoholization temperature. Finally, PEs with spherical morphology and high bulk density (over 0.35 g/ml) were obtained, without reactor fouling. (c) 2006 Elsevier B.V. All rights reserved.