This book focuses on the fundamentals of sediment transport in surface waters. It covers sediment properties, open channel flows, sediment particle settling, incipient motion, bed forms, bed load, suspended load, total load, cohesive sediments, water-sediment two-phase flows, hyperconcentrated flows, debris flows, wave-induced sediment transport, turbidity currents, and physical modeling. Besides the primary context of river sedimentation, this book extensively covers sediment transport under coexisting waves and currents in coasts and estuaries,　hyperconcentrated and debris flows in rivers, as well as turbidity currents in lakes, reservoirs, channels, and the ocean. It includes a chapter on the water-sediment two-phase flow theory, which is considered the basis of many sediment transport models. It introduces some special topics have that emerged in recent years, such as the transport of mixed cohesive and noncohesive sediments, biofilm-coated sediments, and infiltrated sand within gravel and cobble beds. The text merges classical and new knowledge of sediment transport from various sources in English and non-English literature and includes important contributions made by many scientists and engineers from all over the world. It balances the breadth, depth, fundamental importance, practical applicability, and future advancement of the covered knowledge, and can be used as a text and reference book. The chapters are arranged in a useful sequence for teaching purposes. Certain homework problems are prepared, which also highlight the important topics for instructors to select. Solutions to homework problems are available from the author by request.