The effect CMMS (cyclohexylmethyl dimethoxysilane/DPCS (diphenyl dichloridesilane) as electron donor on the polymerization of propene was discussed. The solvent polymerization of propene was carried out in 60 ℃ at 1. 04×105 Pa. It was found that the catalyst activity has gone up by 20 per cent when CMMS/DPCS=1/3 under the given condition . The concentration of active titanium center (C) was determined with kinetic-molecular weight method. It turns out that the active titanium centers do not increase by using mixedelectron donor CMMS/DPCS as compare with CMMS as electron donor but can increase Kp by 20% In addition

average-chain length can be achieved in five minutes with CMMS/DPCS.So polymer isotacticity index does not change with the time of polymerization.