The polymerization of propylene combined with bis(6-heptenyl)zinc (BHZ) catalyzed by rac-Me2Si[2-Me-4-Ph-Ind](2)ZrCl2/MAO was investigated. BHZ acts as both a comonomer and a chain transfer reagent, which was verified by H-1 NMR and C-13 NMR spectra. A novel effect of BHZ on the molecular weight and rheologic properties of the product was explained by the production of LCB.