The book ‘Animal Diversity and Taxonomy’ has been written on the overwhelming demand of the students pursuing B.Sc. and M.Sc. from different universities of India. The book aims to cater for long lasting student`s need. This book is very carefully divided in 19 chapters. Chapters of general principles of taxonomy, five kingdom concept, binomial nomenclature, concept of protozoa and metazoa, levels of body organization, bases of classification and animal diversity have been added separately to achieve better understanding of classification and diversity of animals. Inclusion of habit, habitat and salient features with their morphology, internal anatomy and physiology of Amoeba, Entamoeba, Paramecium, Euglena, Plasmodium, Trypanosoma, Leishmania, Leucosolenia, Sycon, Obelia, Aurelia, Beroe, Taenia, Fasciola, Ascaris, Dracunculus, Woucheraria, Nereis and Leech is the great achievement of this book. Illustrations have been specially designed with great dexterity, accuracy and in conformity in their textual description. At the end of this book an illustrative glossary of technical terms are given for better understanding of technical terms. It is intended primarily as a text book for honours and under graduate students of Indian universities. However, the students of higher classes, the candidates preparing competitive examinations, and the subject teachers may also find it useful as a handy guide for reference. The book follows essentially the patterns set by other Indian writers. With recent studies, modification in the phylogeny of animal classification became necessary. This has been adopted in the text where appropriate and to bring them up to date. In this book the special emphasis has been given to technical terms and other textual matter. The book contains objective, short and long type questions at the end of each chapter. This enterprise is an effort to write an easy-to-understand book in simple language for the students. Characters and classification of each phyla and classes of animal kingdom have been simplified and controversies avoided benefiting our young readers. Therefore, we can that the book is ultimate for the readers.