The encapsulation of the curing agent is a method for preparing latent curing agents for epoxy resins. These curing agents have been used in one-part epoxy systems. In this study, viscoelastic properties of the epoxy resin (diglycidyl ether bisphenol A) containing microcapsule (1-methylimidazole capsulated by solid epoxy) were investigated by the dynamic shear parallel-plate rheometer, at 120°C. The storage modulus, loss modulus, and complex modulus of the epoxy resin system containing 20 Phr microcapsules (latent curing agent) are used for determining the curing behavior of this epoxy resin system. The results showed that at different times, three different regions are observed in the viscoelastic behavior of the epoxy resin/microcapsule system at 120°C. Also, in the presence of microcapsules in these three stages, the storage module is more than the loss module. Fourier transform infrared spectroscopy and Differential scanning calorimetry test also confirmed this curing reaction.