Objective To investigate the main characteristics of intro-abdominal microbial infection and the risk factors for it after pancreaticoduodenectomy. Methods Clinical data of 200 patients underwent pancreaticoduodenectomy at the First Affiliated Hospital of Xinjiang Medical University from Sep. 2008 to Sep. 2013 were reviewed retrospectively to investigate the main characteristics of abdominal microbial infection after pancreaticoduodenectomy and risk factors for it. Results Of the 200 patients, cultures of drainage fluids were positive in 78 patients, and 42 of them(21.0%) met the diagnosis of intra-abdominal infection criterion. One hundred and eighty-five pathogenic strains were isolated totally, 64 strains of them(34.6%) were Gram positive cocci, 103 strains(55.7%) were Gram negative bacilli, and 18 strains (9.7%) were fungus. The top 5 kinds of bacteria in order were Staphylococcus aureus(31 strains), Pseudomonas aemginosa(28 strains), Escherichia co1i(22 strains), Klebsiella pneumoniae(18 strains), and Enterococcus faecium (14 strains). Most of the pathogens were resistant to broad-spectrum antibiotics. The resistance rate of Pseudomonas aeruginosa was 60.7%(17/28) to imipenem. Extended spectrum beta lactamases(ESBLs)-producing strains accounted for 22.7%(5/22) and 33.3%(6/18) in Escherichia coli and Klebsiella pneumoniae respectively. The detection rate of methicillin resistant staphylococcus aureus(MRSA) was 45.2%(14/31) in Staphylococcus aureus. Multivariate logistic regression analysis results showed that status of pancreatic fistula and pulmonary infection were the risk factors for intraabdominal infection, patients with high grade of pancreatic fistula(OR=16.252, P=0.003) and with pulmonary infection (OR=2.855, P=0.017) had higher incidence of intra-abdominal infection. Conclusion Gram negative bacilli is the main pathogenic bacteria of abdominal drainage fluids cultivation of microbiology after pancreaticoduodenectomy. Most of them have multi-drug resistance characteristic. Positive prevention and treatment of pancreatic fistula and pulmonary infection can reduce the incidence of intra-abdominal infection.