Abstract: OBJECTIVE To monitor the detection rate and drug resistance of Acinetobacter baumannii(ABA) in Tongji Hospital, and understand the prevalence status of ABA, in order to provide references for the clinical prevention and treatment of ABA infections. METHODS ABA strains clinically isolated from 2011 to 2015 from ICU of Tongji Hospital were statistically analyzed. Bacterial identification and drug sensitivity were detected by VITEK-2 automatic bacteria identification system, and the results of antimicrobial susceptibility were determined according to CLSI 2015 M100-S25 criteria. All the data were analyzed by WHONET 5.6 software. RESULTS Totally 1079 strains of Ab were detected from 5 084 positive specimens from ICU from 2011 to 2015, with the detection rate of 21.22%, including 1 026 strains of carbapenem-resistant AB(CRAB), accounting for 95.09%. The detection rate was generally on the rise in five years. Among the specimens, 88.88% were sputum specimens, 6.21% were blood specimens, and 4.91% were other types of specimens. In 5 years, the resistance of Ab isolated from our ICU to cefoperazone / sulbactam, minocycline had significantly changed, to tigecyclin was lower, to other antibiotics were all above 70%, and to tobramycin, and amikacin increased year by year. CONCLUSION The isolation rate and drug resistance of ABA are severe in the ICU of the hospital, showing an upward trend. We should master the epidemic trend and characteristics, select the sensitive antibiotics according to the drug sensitivity results, and use the antibiotics reasonably.