ObjectiveTo investigate the bacterial spectrum and antimicrobial resistance of peritoneal dialysis (PD)related peritonitis, and provide evidence for rational antimicrobial use. MethodsClinical data of 120 patients with PDrelated peritonitis in a hospital from January 2013 to December 2014 were retrospectively analyzed. Results91 cases (75.83%) showed positive result in bacterial culture, 93 pathogenic strains were cultured, including 73 (78.49%) grampositive and 13 (13.98%) gramnegative bacterial strains, the most common grampositive bacteria was Staphylococcus epidermidis (n=38, 40.86%)， and the main gramnegative bacteria was Escherichia coli (n=3, 3.23%). Grampositive strains had high resistance rates to penicillin, erythromycin, and oxacillin (93.65%, 69.57%, and 64.41% respectively), while resistance rates to vancomycin and linezolid  were both low (2.90% and 1.47% respectively), and were  sensitive to teicoplanin, tigecycline, and nitrofurantoin. Gramnegative bacteria had high resistance rates to cefazolin, cefuroxime, and ampicillin（50.00%,  37.50%, and 37.50% respectively）, but were sensitive to imipenem, tobramycin, and piperacillin. Resistance rates of grampositive and gramnegative bacteria to gentamicin and levofloxacin were both low. Nonstandard operation during dialysate exchange was the most common cause of peritonitis (56.67%), most peritonitis were grampositive bacterial infection（79.41%）；while gramnegative bacteria  were the main pathogens of diarrheainduced peritonitis (52.63%). The cure rates of grampositive bacteria, gramnegative bacteria,and negativecultured peritonitis were 92.96%, 76.92%, and 86.21% respectively, difference was not statistically significant（χ2=3.39，P=0.18）. ConclusionGrampositive bacteria are major pathogens in PDrelated peritonitis, and are usually caused by the bacteria through  dialysis catheter due to nonstandard operation during dialysate exchange. Firstgeneration cephalosporins are not recommended as empirical therapy against grampositive bacteria, while vancomycin is still the best choice. Thirdgeneration cephalosporins and aminoglycosides are recommended as empirical therapy against gramnegative bacteria. Gentamicin and levofloxacin can be used alone as empirical therapy in special circumstances.