The SMiRT 27 in Yokohama Japan will discuss what is "Next Generation Structural Mechanics in Reactor Technology" on the bases of lessons learned from the Fukushima Daiichi Nuclear power plant accident. It will be co-hosted by JASMiRT and Atomic Energy Society of Japan. Plenary lectures, special sessions, tutorials, and workshops will be organized to discuss this topic in addition to the regular sessions. The SMiRT 27 aims to bring together leaders, managers, engineers, plant operators, regulators and academia working in the field of nuclear technology to make greater contribution for achievement of higher reactor performance. We hope that various efforts to improve worldwide nuclear safety, long-term operation in consideration of aging issues, communication between regulatory authorities and industries, standardization of reactor-independent codes/standards, etc. will be central issues in SMiRT 27, to establish "Next Generation Structural Mechanics in Reactor Technology."