Pathogenic microorganism identification has evolved from traditional methods such as morphology and serology at the pathogen level to molecular and genomic levels, greatly improving the accuracy of identification. Guided by the needs of key supporting technologies for the prevention and control of infectious disease pathogen identification, this book focuses on commonly and frequently occurring infectious diseases in China, as well as newly emerging infectious diseases in recent years. It has established or optimized hundreds of standardized identification techniques for infectious disease pathogens, further improved the pathogen identification and preservation technology system in China, filled the gaps in nearly 100 kinds of pathogen identification techniques (especially molecular-level identification techniques), and enhanced the ability to identify and discover pathogenic microorganisms of infectious diseases. It also provides a clearer and more accurate description of the characteristics of infectious disease pathogens.