Across many disciplines of engineering, dynamic problems of structures are a primary concern. Civil engineers, mechanical engineers, aircraft engineers, ocean engineers, and engineering students encounter these problems every day, and it is up to them systematically to grasp the basic concepts, calculation principles and calculation methods of structural dynamics. This book focuses on the basic theories and concepts, as well as the application and background of theories and concepts in engineering. Since the basic principles and methods of dynamics are applied to other various engineering fields, this book can also be used as a reference for practicing engineers in the field across many multiple disciplines and for undergraduate and graduate students in other majors as well. The main contents include basic theory of dynamics, establishment of equation of motion, single degree of freedom systems, multi-degree of freedom systems, distributed-parameter systems, stochastic structural vibrations, research projects of structural dynamics, and structural dynamics of marine pipeline and riser.