This paper presents a simulation model for investigating the dynamic performance of molten carbonate fuel-cell power-generation systems. The simulation model consists of nine types of component models: fuel cell, external reformer, steam generator, water separator, rotation equipment (including compressor, blower, pump and expander), heat exchanger, DC/AC invertor, pipeline and control valve. The model performance is demonstrated by applying it to calculate the load-following capability of the system under various step changes and to identify the potential component operation problems at load-following modes.