Abstract: In this paper, the rheological behavior of a hydantoin epoxy resin for resin transfer molding(RTM) was studied with DSC analysis and viscosity experiments. A rheological model based on dual-Arrhenius equation was established to simulate rheological behavior of the resin. The estimated viscosity of the model was in good agreement with that of the experiments. The processing window of the resin system can be well determined for the process based on the developed model. The rheological model is important for processing simulation of resins and quality control of RTM processing for high performance composites.