ObjectiveTo investigate the clinical characteristics and prognostic factors of severe viral pneumonia induced moderate to severe acute respiratory distress syndrome (ARDS). MethodsTwenty patients with severe viral pneumonia induced moderate to severe ARDS admitted in the Respiratory Intensive Care Unit(RICU) in Xiangya Hospital of Central South University from January 2011 to April 2014 were included in the study.The clinical characteristics and prognostic factors were analyzed retrospectively by analysis of variance(ANOVA). ResultsFive patients developed secondary bacterial infections,while three patients developed secondary fungal infections,among which 2 patients developed both bacterial and fungal infections.Fourteen patients died during hospitalization. ANOVA revealed that gender,body temperature,respiratory frequency,pulse frequency,white blood cell count (WBC),hemoglobin(Hb),platelet(Plt),prothrombin time (PT),albumin(Alb),blood urea nitrogen(BUN),serum creatinine(Scr),total bilirubin(TBIL),serum sodium,serum potassium,erythrocyte sedimentation rate (ESR),C-reactive protein(CRP),procalcitionin(PCT),pH,PaCO2,PaO2 and FiO2 were not significantly different between the dead patients and the alive patients (P>0.05).Whereas the age,length of hospital stay,duration of mechanical ventilation,oxygenation index,and the severity of ARDS were significantly different between the dead patients and the alive patients (P<0.05). ConclusionAge,oxygenation index and severity of ARDS can influence the prognosis of patients with severe viral pneumonia induced moderate to severe ARDS.