This paper presents analyses of composite beam which is composed of H-section steel and reinforced concrete slab. Analyzed models were simply supported beams and H-shaped structural frames which were composed of 2-story columns and 1-span beam. In analyzing simply supported beams, some other factors (for example, thickness of fire protection, width of slab etc ...) were considered. In analyzing H-shaped structural frames, two models we= considered. One model has composite beam, and the other model has H-section steel beam only. From the results of these analyses, it is concluded that the fire resistance of the structural frame with H-section steel beam and the structural frame with composite beam is almost the same.