In a more modern sense, Virology has acquired a broader significance as it encompasses the study of ecology, evolution of viruses, interaction among viruses and other microorganisms, and the ability of viruses to deliver their own and heterologous genetic information into cells. There are many books on the subject of Virology but updated information is not incorporated in the edition. This book has covered a range of syllabus and the student is an easy way to go through this book content. This book would serve not only for undergraduate but postgraduate students of biotechnology and also research scholar of various universities.