This book is about the wide subject of the microbiology or more precisely we can say that this book is a discussion about the topic of clinical microbiology and it related topic. It is simply written ond fully equipped with the knowledge of the thousands of researcher and experts have contributed throughout the development processes of clinical microbiology. When person as a reader dive into this book, firstly they will be introduced the first chapter of the book which give in detail introduction of the clinical microbiology and history of the bacteriology and classification of bacteria. The second chapter is totally dedicated to the infections which are caused by the gram positive bacteria. Such as bacillus anthrax, clostridium, pneumococcus and corynebacterium etc. Study of all of the above gram-positive bacterium is important in the clinical study of the infection related to them. The third chapter briefly describes the gram-negative bacteria such as: salmonella, sighella, Klebsiella and Proteus. And then the chapter four comes to give a wide perspective about the microscopy covering the wide range of topic such as: the types of the microscopy and the microscope their principle and the applications in the real world. Finally the chapter five describes the growth kinetics of the bacteria and the type of the microbial growth.