The curing reactions of an epoxy system composed of a diglycidyl ether of bisphenol A (BADGE n=0) and m-xylylenediamine (m-XDA) were studied. Two models, the first based solely on chemical kinetics and the second accounting for diffusion, were used and compared to the experimental data. The epoxy resin was used as received in a first series of experiments. In a second series of experiments, the resin was purified in vacuo (180 degrees C and 1 mmHg). The inclusion of a diffusion factor in the second model allowed for the cure kinetics to be predicted over the whole range of conversion covering both pre- and postvitrification stages. The investigation was made in the temperature range 50-110 degrees C, which is considered optimum for the isothermal curing of the epoxy system studied.