ObjectiveTo investigate the distribution and antimicrobial resistance of pathogens causing bacterial peritonitis, provide laboratorial guidance for rational use of antimicrobial agents. Methods Pathogenic strains isolated from peritoneal fluid specimen of patients with peritonitis in the Affiliated Hospital of Xuzhou Medical University in 2011-2015 were collected, performed bacterial identification and antimicrobial susceptibility testing, distribution of pathogens and antimicrobial resistance were analyzed. ResultsA total of 491 strains were collected, including 291（59.26%）strains of gramnegative bacilli, 196（39.92%）of grampositive cocci, and 4 (0.82%) of fungi. The top 5 pathogens were Escherichia coli(30.14%), coagulase negative staphylococcus(12.22%), Staphylococcus aureus (10.39%), Klebsiella pneumoniae (8.55%) , and Enterococcus  faecium(6.52%). Antimicrobial resistance rates of Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa to imipenem were 4.90%, 31.04%, 77.28% and 26.27% respectively. Methicillinresistant Staphylococcus aureus(MRSA) and methicillinresistant coagulase negative staphylococcus(MRNCS) accounted for 56.02% and 70.02% respectively. ConclusionThe main pathogens causing bacterial peritonitis are gramnegative bacilli, Escherichia coli ranks first; resistance of pathogens is serious, standard use of antimicrobial agents should be strengthened to reduce the emergence of drugresistant strains.