Abstract: Objective:To learn the etiological characteristics and drug resistance of community-acquired pneumonia(CAP) in Southern District of Beijing Tongren Hospital,so as to provide evidence for empiric antibiotic therapy.Methods:Collect specimens of sputum or blood for bacterial culture from 205 patients who met the diagnostic criteria of community-acquired pneumonia,apply serological methods to detect Mycoplasma pneumoniae antibody,Chlamydia pneumoniae antibody and Legionella pneumophila antibody.Results:Pathogens isolated were 79 cases(40.9%) from 193 patients,in which Klebsiella pneumoniae ranks first,followed by Streptococcus pneumoniae;Mycoplasma pneumoniae is the most common in 200 cases of serological examination.The sensitive antibiotics for pathogens were identified.Conclusions:Based on the test of drug resistance,the pathogens sensitive antibiotics should be used for treatment of CAP patients.