A novel MgCl_2-supported Ziegler-Natta catalyst containing diethyl diisopropylsuccinate donor was pre- pared and propylene polymerizations with the combination of such catalyst and four external donors were inves- tigated in detail.The catalyst was compared with a commercial one with phthalate as internal donor in terms of catalytic activity,hydrogen sensitivity and stereospecificity in propylene polymerization.The molecular weight, molecular weight distribution and microstructure of the produced polypropylenes were compared also.It was found that the novel catalyst containing succinate internal donor showed higher activity and higher stereospecificity than those with phthalate as internal donor.Consequently,polypropylenes obtained by the succinate-based catalyst showed high molecular weight,high melting temperature,high isotactic index and broad molecular weight distribu- tion than those obtained with the commercial catalyst. A novel MgCl 2-supported Ziegler-Natta catalyst containing pre-pared and propylene polymerizations with the combination of such catalysts and four external donors were in tigated in detail. The catalyst was compared with a commercial one with phthalate as internal donor in terms of catalytic activity, hydrogen sensitivity and stereospecificity in propylene polymerization. molecular weight, molecular weight distribution and microstructure of the produced polypropylenes were also also .It was found that the novel catalyst containing succinate internal donor showed higher activity and higher stereospecificity than those with phthalate as internal donor. Conclusion, polypropylenes obtained by the succinate-based catalyst showed high molecular weight, high melting temperature, high isotactic index and broad molecular weight distributive than those obtained with the commercial catalyst.