Earthquake and tsunami disasters have been increasing rapidly and globally in the last quarter-century. The purpose of this book is to provide essential knowledge and information on the mitigation of earthquakes and tsunamis for graduate students, young researchers, and geotechnical engineers. It begins by presenting recent cases of earthquakes that have occurred in the world, referring to tsunamis and soil liquefaction and how to cope with such disasters. The final chapter proposes strategies for disaster mitigation against in Japan earthquakes and tsunamis in the future.