Abstract: The viscosity-temperature and viscosity-time characteristic curves of high-temperature resistant glycidylamine epoxy system were measured by the rotational rheometer to investigate the chemorheological characteristics of the resin system. Daul Arrhenius model and engineering viscosity model were established compared with each other to analyze the isothermal viscosity characteristic curves of the resin system. Then a second-order exponential viscosity model was proposed to predict the viscosity change law of the resin system. The results show that the prediction accuracy and applicability of the second-order exponential viscosity model are better than Daul Arrhenius model and engineering viscosity model. The predicted viscosity is in a good agreement with the experimental data. This phenomenological formula of viscosity versus temperature and time can be used to predict the processing window of the resin system conveniently and accurately, and point out the technology problems in the engineering applications.