In performing real-time simulation of electric circuits, the time step is constrained by the computation, so there is a limit to be small it. In addition, when electric transient analysis simulation represented by SPICE is applied to circuits including switching operation such as Switched-Mode Power Supplies (SMPSs), the time step must be sufficiently shorter than the high-speed switching operation. For these reasons, real-time simulation of SMPSs is very difficult. So, various methods have been proposed in previous research to make it possible, but their accuracy are problematic. In this paper, we propose a real-time simulation method using averaged models of SMPSs. Father more, we targeted LLC Current Resonant Converter (LLC converter), which is difficult to model, and examined the modeling method. In addition, the obtained model is implemented in real-time simulator, and its accuracy and real-time simulation feasibility were verified.