The rationale for the antibiotic treatment of viral community-acquired pneumonia (CAP) in adults was analyzed to develop a clinical reference standard for this condition.Clinical data from 166 patients diagnosed with viral pneumonia across 14 hospitals in Beijing from November 2010 to December 2017 were collected.The indications for medications were evaluated,and the rationale for the use of antibiotics was analyzed.A total of 163 (98.3％) patients with viral pneumonia were treated with antibiotics.A combination of C-reactive protein (CRP) and procalcitonin (PCT) was used as markers to analyze the possible indications for antibiotic use.With threshold levels set at 0.25 μg/L for PCT and 20 mg/L for CRP,the rate of unreasonable use of antibiotics was 55.2％.By contrast,at a CRP level threshold of 60 mg/L,the rate of antibiotic misuse was 77.3％.A total of 39 of the 163 (23.9％) patients did not meet the guidelines for drug selection for viral CAP in adults.The unreasonable use of antibacterial drugs for the treatment of viral CAP in adults is a serious concern.Clinicians must reduce the unnecessary use of antibiotics.