Abstract: Community-acquired pneumonia (CAP) is one of the worldwide diseases with high morbidity and mortality worldwide. To identify the pathogenic microorganisms for CAP can provide the best therapeutic strategies of antimicrobial agents; improve the outcome of patients, with great importance for epidemiology monitor and public health planning. Traditional microbiological techniques such as microbiological culture and urinary antigen tests are simple and convenient, but limited by its imperfection in timeliness and sensitivity, which prone to be affected by sample management and cultural conditions. Microbial nucleic acid detection got rapidly development in recent years. The nucleic acid amplification tests (polymerase chain reaction, PCR) can identify pathogenic genetic materials quickly with high sensitivity and specificity. Next-generation sequencing had revolutionized the identification of microbes in respiratory tract, which detects conserved gene sequence of multiple pathogens simultaneously,and provides unprecedented depth and width for respiratory microbiome analysis. The improvement of traditional microbiological methods and advance in nucleic acid detection methods, as well as optimal combination of multiple techniques will provide comprehensive and accurate pathogenic information for CAP diagnosis. In addition, the investigation on the characteristics of microbiome makes promise to reveal the relation between CAP and dysbiosis of microbiome in lower respiratory tracts, and brings novel insights for better management of CAP patients.