Community-acquired pneumonia is caused by a variety of pathogenic microorganisms such as out-of-hospital bacteria, viruses, chlamydia and mycoplasma. Unlike nosocomial infections, community-acquired pneumonia is sensitive to a variety of antibiotics. The pneumonia caused by Staphylococcus aureus is best treated with appropriate antibiotics based on drug sensitivity tests, usually using sensitive penicillin antibiotics or β-lactam antibiotics, but also vancomycin, rifampicin, phosphomycin, etc. Third, community-acquired pneumonia caused by Pseudomonas aeruginosa, generally choose the third generation of cephalosporin antibiotics, or quinolone antibiotics, and penicillin antibiotics. For community-acquired pneumonia caused by Klebsiella pneumoniae, ampicillin, piperacillin, and amikacin, as well as ceftazidime may be preferred. For the treatment of community-acquired pneumonia the principles of medication are sensitivity, adequate dosage, and adequate course of treatment.