ObjectiveTo understand the pathogenic characteristics of intraabdominal infection after appendectomy in patients with appendicitis. MethodsClinical data of patients undergoing appendectomy in a hospital from January 2013 to December 2015 were analyzed retrospectively, pathogenic characteristics, treatment, and prognosis of patients with intraabdominal infection were analyzed. ResultsA total of 431 patients undergoing appendectomy were investigated, 38 (8.82%) developed intraabdominal infection. 36 strains of pathogenic bacteria were isolated, 34 (94.44%) of which were gramnegative bacteria, mainly Escherichia coli(n=29，80.55%）; 2 (5.56%) strains were grampositive bacteria, 1 of which was Staphylococcus aureus, and the other was Enterococcus avium. The resistance rates of 29 strains of Escherichia coli to commonly used antimicrobial agents (amoxicillin, piperacillin, ticarcillin, cefuroxime, ceftazidime, and cefalotin) were 72.41%93.10%, none of strains were found to be resistant to piperacillin/tazobactam, meropenem, imipenem, and amikacin. ConclusionEscherichia coli is the most common pathogen causing intraabdominal infection after appendectomy and it has high resistance rates to most commonly used antimicrobial agents, piperacillin/tazobactam, amikacin, and carbapenems are recommended for treating intraabdominal infection after appendectomy.