Advanced Dairy Chemistry-l: Proteins is the first volume of the third edition of the series on advanced topics in Dairy Chemistry, which started in 1982 with the publication of Developments in Dairy Chemistry. This series of volume~ is intended to be a coordinated and authoritative treatise on Dairy Chemistry. In the decade since the second edition of this volume was published (1992), there have been considerable advances in the study of milk proteins, which are reflected in changes to this book. All topics included in the second edition are retained in the current edition, which has been updated and considerably expanded from 18 to 29 chapters. Owing to its size, the book is divided into two parts; Part A (Chapters 1-11) describes the more basic aspects of milk proteins while Part B (Chapters 12-29) reviews the more applied aspects. Chapter 1, a new chapter, presents an overview of the milk protein system, especially from an historical viewpoint. Chapters 2-5, 7-9, 15, and 16 are revisions of chapters in the second edition and cover analytical aspects, chemical and physiochemical properties, biosynthesis and genetic polymorphism of the principal milk proteins. Non-bovine caseins are reviewed in Chapter 6.