In the both fields of civil engineering and architectural constructions, Hybrid Structures attract attention as the third structure which is different from steel structures and reinforced concrete structures. Hybrid Structures combine different structural materials such as steel or concrete and they show excellent characteristic that is never provided by a single material use. At present, the application of Hybrid Structures to Japanese railway constructions is dramatically on the increase, making the most of structural merits. In this situation, many kinds of concerned research and development are being propelled and model codes of design for Hybrid Structures are set up by Japan Society of Civil Engineers as the central sponsor. In the first half of this paper, several application cases to the railway constructions are introduced and in the latter half, its development is reviewed.