Three reactive epoxy-amine systems based on diglycidyl ether of bisphenol A (DGEBA) with 4,4＇-diaminodiphenylsulfone (DDS), 4,4＇-methylenebis [3-chloro 2,6-diethylaniline] (MCDEA), and 4,4＇-methylenebis [2,6-diethylaniline] (MDEA), were studied during isothermal curings at 140 and 160 degrees C. The simultaneous kinetic and dielectric studies allow to express conductivity, sigma in terms of conversion, x, and of glass transition temperature, T-g. The conductivity, sigma(0), of the initial monomer mixture and, sigma(infinity) of the fully cured network are measured. It is found that : The glass transition temperature, T-g, versus conversion, x, curves follows the equation of Di Benedetto modified by Pascault and Williams There exists a linear relation between log sigma/log sigma(0) and T-g. So, it is possible to predict both kinetic and dielectric behaviors of these epoxy-amine systems by the knowledge of T-g0, Delta C-p0, and sigma(0), respectively, glass transition temperature, heat capacity, and conductivity of initial monomer mixture, T-g infinity and Delta C-p infinity, and a,, respectively, glass transition temperature and heat capacity and conductivity of fully cured network.