The express purpose of Time-Varying Network Optimization is to describe, in a unified and self-contained manner, a series of models, propositions, and algorithms developed in recent years on time-varying networks. References and discussions on relevant problems and studies that have appeared in the literature are integrated in the book. The book consists of eight chapters, in which the following problems are formulated and examined: (1) the shortest path problem, (2) minimum-spanning tree problem, (3) maximum flow problem, (4) minimum cost flow problem, (5) maximum capacity path problem, (6) quickest path problem, (7) multi-criteria problem, and (8) the generalized flow problem. The time-varying traveling salesman problem and the Chinese postman problem are presented in a chapter together with the time-varying generalized problem. While these topics will be described all within the framework of time-varying networks, our plan is to make each chapter relatively self-contained so that each can be read separately.