||Objective: To investigate the characteristics of spectrum and drug resistance of pathogens causing sepsis in patients with severe acute pancreatitis(SAP). Methods: The clinical data of 63 SAP patients with sepsis admitted in Department of Hepatobiliary, People's Liberation Army General Hospital from January 2014 to December 2015 were retrospectively studied. There were 47 males and 16 females, aged from 22 to 73 years, with an average age of (52+/-11)years. Samples were collected mainly from: (1)pancreatic and peripancreatic necrosis and abdominal drainage; (2)bile; (3) blood or deep venous catheter; (4) sputum and tracheal catheter and thoracic drainage; (5) urine. Strain identification and drug-resistance test were preformed on positive specimens. Results: Of 244 pathogenic isolates, mainly derived from abdominal cavity(36.0%), blood stream (14.0%), central venous catheter(11.8%), necrotic tissue(9.1%) and sputum(8.1%); 154(63.1%) were gram-negative bacteria, 68 cases(27.9%) were gram-positive bacteria and 22 cases(9.0%) were fungi respectively. The top six common pathogens isolated were E. coli(16.0%), E.faecium and faecalis(15.2%), P.aeruginosa(10.7%), K.pneumonia(9.8%), Acinetobacter baumanni(8.2%), Stenotrophomonas maltophilia(5.3%)respectively. The detection rate of E. coli and K. pneumonia extended-spectrum beta-lactamases(ESBL) was 84.6%(33/39) and 70.8%(17/24), the resistance rate to imipeniem was 12.8% and 25.0%, to cefperazone-sulbactam was 28.2% and 29.2%. As to P. aeruginosa and Acinetobacter bacillus, the resistance rate to imipeniem was 50.0% and 75.0%, to cefperazone-sulbactam was 42.3% and 70.0%; Stenotrophomonas maltophilia was completely resistant to cefperazone-sulbactam, but sensitive to minocycline, SMZ-TMP with the resistance rate less than 40.0%. Gram-positive bacterium strains mainly included E. faecium(38.2%, 26/68), E.faecalis(16.2%, 11/68) and Staphylococcus(35.3%, 24/68) which maintained high sensitivity to vancomycin, teicoplanin and linezolid, there was only one isolate resistant to vancomycin. Candida were the sole pathogens of fungal infections, sensitive to common antifungal drugs overall. Conclusions: The gram-negative bacteria are the predominant pathogens mainly including ESBL-producing isolates(E.coli and K. pneumonia) and non-fermentation bacteria(P.aeruginosa and Acinetobacter bacillus) causing sepsis in SAP. The infection rate and drug-resistance rate of these two kinds of pathogens are relatively higher.