Abstract: Objective　To investigate the incidence and risk factors of antibiotic-associated diarrhea (AAD) of pediatric patients with severe bacterial pneumonia. Methods　Clinical data of 1086 pediatric patients with severe bacterial pneumonia from January 2010 through January 2014 were recruited. The incidence and risk factors of AAD were retrospectively analyzed. Results　The incidence of AAD in 1086 pediatric patients with severe bacterial pneumonia was 36.74%. The incidence of AAD in patients younger than 2 years old were higher than that in those older than 2 years, once or more times of mechanical ventilation history were higher than that with no arrangements of this treatment, administering of combined antibiotics therapy were higher than that with single antibiotics, and the incidence of AAD due to amoxicillin/clavulanate, piperacillin/tazobactam, cefoperazone/sulbactam in pediatric patients were 43.55%, 43.75%, and 45.03%, respectively. Three β-lactam/β-lactamase inhibitors above were risk factors of AAD through multivariate Logistic regression analysis. Conclusion　The high incidence of AAD in pediatric patients with severe bacterial pneumonia was associated with some risk factors, including younger than 2 years old, mechanicalventilation, combined antibiotics therapy and administration of β-lactam/β-lactamase inhibitor (amoxicillin/clavulanate,piperacillin/tazobactam, cefoperazone/sulbactam).