In South Korea, the most common floor system installed on steel frames have been deck slab system. Disadvantage of this system is increasing construction duration due to concrete curing and additional fireproofing protection works. As fireproofing protection installed by people handwork had low quality and material wastes, floor systems that had fire resistance performance and easily applied to steel frames started being developed. Prefabricated Composite Floor System was also developed to apply to steel structures without fireproofing protection and features of this system were largely influenced by Phase Change Material filled inside the system. Phase Change Material could be differently made by additives and some materials were developed to enhance the fire resistance performance of systems by changing additives. In this research, the fire resistance performance of Prefabricated Composite Floor system with infilled different Phase Change Material was evaluated and predicted by using finite element analysis program ABAQUS/CAE 6.10-1. In addition, the effect of wire meshes and the type of PCM were investigated by using temperature distributions and displacements during 2 hours fire test modelled at finite element program.