The rate equation of the ionic solution polymerization may be expressed in．general by r=—dM—dθ=kMmCn where M and C denote the concentrations of the monomer and the catalyst in the solu-tion respectively．m and n are kinetic parameters characterizing the polymerization sys-tem．In order to control the polymerization process or to design an adequate reactor system，it is required to regulate the reaction rate to conform with the heat transfer capacity of the system．Various operating schemes were postulated and their rate behavior during the reaction obtained by integrating the fundamental rate equation for these schemes．The results obtained for batch polymerization under control at isothermal conditions are as follows.