This book introduces the fundamental knowledge of seismic design of building structures, from seismology to earthquake engineering.It intro-duces the basic concepts of seismic design with several engineering examples in China to facilitate readers to understand the concepts in the design codes and its applications. This book can serve as a guide for instructors, graduate students and practicing engineers. We hope it will contribute to the teaching of earth-quake engineering and its applications to practice, as well as to the formula tion and evolution of research programs.