A novel MgCl2-supported Ziegler-Natta catalyst containing 2-isoamyl-2-isopropyl-1,3-propandiol dibenzoate donor for propylene polymerization was studied, and compared with catalysts with different internal donors, such as benzoate, phthalate and diether, in polymerization dynamic behavior, activity, hydrogen response and stereospecificity. It was found that there are two highly isospecific active sites in the catalyst with dibenzoate internal donor system and the effections of temperature are different on the performances of the two highly isospecific sites. (C) 2004 Elsevier Ltd. All rights reserved.