Abstract: The design strengh of the concrete used for ultra-high-rise buildings in Japan has already surpassed 200N/mm2. The overwhelming majority of which were built with the precast construction method. This fasion of ultra-high-rise RC buidings is largely due to the development of ultra-high-strength materials, the conception of new design methodologies, and the innovation in construction technologies. In this area, Japan is the technology leader in the world. This paper includes an introduction of the latest trends of this area in Japan, as well as an overview of the relationship between the ultra-strong materials and a precast concrete structure. It provides also an insight into the recent researches and achievements of the author and his team.