A silica-magnesium bisupport (SMB) was prepared by a sol-gel method for use as a support for a metallocene/Ziegler-Natta hybrid catalyst. The SMB was treated with methylaluminoxane (MAO) prior to the immobilization of TiCl4 and rac-Et(Ind)(2)ZrCl2. The prepared rac-Et(Ind)(2)ZrCl2/TiCl4/MAO/SMB catalyst was applied to the ethylene-hexene copolymerization with variable amounts of 1-hexene used. The catalytic activity of rac-Et(Ind)(2)ZrCl2/TiCl4/MAO/SMB showed a volcano feature with respect to the amount of comonomer used. The melting point attributed to the Ziegler-Natta catalyst was not changed significantly, while that attributed to the metallocene catalyst was broadened and gradually shifted to the lower temperature with increasing I-hexene content. The number of chemical composition distribution (CCD) peaks was increased and the short chain branches were distributed over the lower temperature region with increasing 1-hexene content. The majorities of lamella distributions whose content was more than 50 wt.% shifted to the smaller lamella size with increasing 1-hexene content. The average sequence length of ethylene was steadily decreased with increasing comonomer content, while that of 1-hexene was not changed significantly. Both blocky sequence ([EHH]) and non-blocky sequence ([EHE]) were increased with increasing comonomer content. However, the increasing rate of blocky sequence formation was much higher than that of non-blocky sequence. (c) 2006 Elsevier B.V. All rights reserved.