This study deals with the structural method in conjunction with deep floor slab that can ensure a sufficient fire resistance capacity from the point of view of lateral side of structure configuration in which asymmetric H-beams are partially buried in the concrete slab. In addition, this method can maximize more the story height reduction effects of slim floor system, as its applied building is higher. Hence, this study analyses fire resistance based on KS F 2257-1, inspecting behavior and temperature property of the fire of slim floor system applied to asymmetric H - beam, by changing the cross-sectional shape of this.