To investigate the drug resistance of Acinetobacter baumannii (A. baumannii) isolated from long-term hospitalized elderly patients in our hospital. A total of 52 isolates of A. baumannii were isolated from September, 2011 to August 2012 from elderly nosocomial patients in our hospital. The types of enzyme production, biofilm-forming ability, drug resistance and carrying resistance genes were tested. The infection of A. baumannii most frequently occurred in respiratory intensive care unit. The main separation sampling was sputum specimens (86.54%)．The multi-drug resistant A. baumannii strains were identified mostly (76.92%). A. baumannii isolates showed the lowest resistant rate to cefoperazone-sulbactam, which was 30.77%. The resistant rates to other antimicrobial agents were over 50%. The positive rate of enzyme production was 82.69%, and the most common production was other hydrolytic enzymes (63.46%). The biofilm-forming strains accounted for 5.77% of the isolates. 9 kinds of resistance genes were found in these 6 extensively drug-resistant strains. The study indicates that the grim situation of drug resistance of A. baumannii isolated from long-term hospitalized elderly patients. It is necessary to strengthen the monitoring of drug resistance, especially in respiratory intensive care unit. Meanwhile, drug resistance surveillance and disinfection and isolation should be strengthened in the endemic areas from where the biofilm-positive strains were isolated, so as to prevent and control the production and spread of multi-drug resistant and extensively drug resistant bacteria.