The book is intended to the students involved in the study of microbiology, immunology, and animal reproduction as an introduction to more extensive studies. An overview of immunology is provided in the book to refer immediately any basic information needed, for further understanding of the subject dealt in this book.The chapters covered may provide the structural component for the basic understanding of the reproductive immunology in animals.It is designed to complement, but not to compete with the few books available with regard to reproduction. The book is profusely illustrated with figures and tables. The concise nature of the book and the simple and clear treatment of the topics, it is hopefully will prove to be useful to all.