The book 'A Textbook of Biotechnology' has been designed for all the undergraduate B.E., B.Tech. and B.Sc. students. The book includes 20 chapters and the various topics are written illustratively in very simple way. This book focuses on cell structures and viruses, carbohydrates, lipids, proteins, cell division, food and beverage, etc. The matter has been presented in a structured manner and in an easy to understand, which can be grasped easily by students of various disciplines. A greater stress has been laid on pictorial representation in the text. There has been a conscious attempt to make proper flow of language and present the contents in simple and lucid manner. This book is very useful for the students of biotechnology and others.