Polymerization of vinyl chloride (VC) with titanium complexes containing Ti-OPh bond in combination with methylaluminoxane (MAO) catalysts was investigated. Among the titanium complexes examined, Cp*Ti(OPh)(3)/MAO catalyst (Cp*; pentamethylcyclopentadienyl, Ph; C6H5) gave the highest activity for the polymerization of VC, but the polymerization rate was slow. From the kinetic study on the polymerization of VC with Cp*Ti(OPh)3/MAO catalyst, the relationship between the M-n of the polymer and the polymer yields gave a straight line, and the line passed through the origin. The M-w/M-n values of the polymer gradually decrease as a function of polymer yields, but the M-w/M-n values were somewhat broad. This may be explained by a slow initiation in the polymerization of VC with Cp*Ti(OPh)3/MAO catalyst. The results obtained in this study demonstrate that the molecular weight control of the polymers is possible in the polymerization of VC with the Cp*Ti(OPh)3/MAO catalyst. (C) 2007 Wiley Periodicals, Inc.