History of conservation of decorated tumuli is reviewed as a part of the history of conservation science in Japan. Decorated tumuli were filled and sealed immediately after being built. However,during subsequent history,they were sometimes reused for various other purposes and,in such cases,their conservation environment was changed. After the Edo period, academic studies have been carried out on decorated tumuli,and it is possible to obtain information about the past environment or state of the decorations through descriptions or sketches in such old documents. Following the Meiji Restoration,decorated tumuli came to be protected by law. Then, after Ozuka Tomb was investigated by various scientists in 1969, decorated tumuli began to be sealed with glass door. After the 1990s, public presentations of decorated tumuli have become more common. An understanding of such history is a prerequisite for the conservation of decorated tumuli
