目的:研究成人社区获得性肺炎（community acquired pneumonia, CAP）病原学特点。方法:收集2017年6月至2019年4月在北京大学第三医院发热急诊就诊的246例经检查排除肺结核、肺部肿瘤、非感染性肺间质性疾病、肺水肿、肺不张、肺栓塞、肺嗜酸粒细胞浸润症及肺血管炎等疾病，确诊社区获得性肺炎病例的呼吸道标本，采用多重实时荧光定量PCR检测方法对19种呼吸道病原体进行检测，回顾性分析本中心成人CAP呼吸道病原体的分布情况。结果:本组所有呼吸道标本核酸检测阳性率为46.7%,其中病毒、细菌、不典型病原体阳性率分别为25.6%、19.9%和18.7%，其中肺炎支原体占18.3%。三种主要的呼吸道病毒依次为流感病毒（14.6%）、副流感病毒(2.8%)和鼻病毒（2.8%）。三种主要的呼吸道细菌为肺炎链球菌（8.5%）、流感嗜血杆菌（6.1%）和肺炎克雷伯杆菌（2.4%）。≥65岁组支原体感染检出率低于<65岁组（2.6%n vs 21.3%，χn 2=10.376，n P=0.001）。n 结论:本组样本中，呼吸道病毒超过呼吸道细菌和肺炎支原体,是社区获得性肺炎的主要病原体。肺炎支原体、流感病毒和肺炎链球菌是位列前三位的病原体。“,”Objective:To investigate the etiologic characteristics of adults with community acquired pneumonia (CAP).Methods:Respiratory tract specimens were collected from 246 cases of community acquired pneumonia in Peking University Third Hospital after excluding tuberculosis, pulmonary tumor, non-infectious pulmonary interstitial disease, pulmonary edema, pulmonary atelectasis, pulmonary embolism, pulmonary eosinophil infiltration and pulmonary vasculitis. Nineteen respiratory pathogens were tested by multiple real-time fluorescent quantitative PCR to investigate the distribution of respiratory pathogens.Results:The positive rate of nucleic acid detection in respiratory pathogens was 46.7%, among which 25.6% was virus, 19.9% atypical pathogens and 18.7% bacteria. The most prevalent viruses were influenza virus (14.6%), parainfluenza virus (2.8%) and rhinovirus (2.8%). The three most prevalent bacteria were n Streptococcus pneumoniae (8.5%), Haemophilus influenzae (6.1%)and n Klebsiella pneumoniae (2.4%). The positive rate of n Mycoplasma pneumoniae was higher in patients <65 years than that in patients≥65 years (21.3% n vs 2.6%, χn 2=10.376, n P=0.001).n Conclusions:Respiratory virus is the leading respiratory pathogens in community acquired pneumonia exceeding bacteria and n Mycoplasma pneumoniae, Influenza virus and n Streptococcus pneumoniae are the top three pathogens in CAP.n