Principles of Passive Supplemental Damping and Seismic Isolation – Second Edition provides theoretical and applied knowledge on various supplemental damping and seismic isolation systems that have demonstrated potential at raising the performance of buildings and bridges under earthquake ground motions while keeping construction costs reasonable. The focus of the book is on passive energy dissipation systems and base isolation systems. Each of the 14 chapters of the book discusses the physical behavior, analytical modeling, experimental investigations, seismic design provisions and practical implementations of various supplemental damping and base isolation systems such as hysteretic dampers, viscous and viscoelastic dampers, self-centering systems, tuned-mass dampers, elastomeric, lead-rubber, metallic and sliding bearings. A sample retrofit project incorporating supplemental damping and base isolation systems in a building that can be used as term projects for a graduate course is described. The book is accompanied by a digital file manager containing two finite element programs capable of running inelastic time history analyses (RUAUMOKO and OpenSees) along with a number of input files required to solve some of problems in the book and execute the sample retrofit project. The book is written for practicing structural engineers, graduate students, and graduate university educators and is particularly aimed as a textbook for an advanced graduate course on the topic of earthquake engineering. The reader must have a strong background on the dynamic analysis of linear and nonlinear structures and be familiar with conventional seismic design principles to fully appreciate the content of the book.