Objective To investigate the genetic features related to drug-resistance of a strain of pan-drug resistant Acinetobacter baumannii. Methods The susceptibilities to 15 antibacterial agents were detected in Acinetobacter baumannii by K-B paper diffusing method. A strain of pan-drug resistant Acinetobacter baumannii was selected. The drug-resistant genes of the selected strain were amplified by polymerase chain reaction (PCR) , including 15 extended-spectrum β-lactamase genes, 3 metal β-lactamase genes, 2 AmpC enzyme genes, 7 aminoglycoside modifying enzyme genes and the genetic markers of integron I and transposons. Results The strain was resistant to 14 antibacterial agents except cefoperazone sodium/ sulbactam. β-lactamases genes ( TEM, OXA-23 and ADC) , aminoglycosides modification enzyme genes [aac(3)- I , aac(6')- I b and ant(3")- I ] , integron I qacEAi-sull and transposon tnpU were positive in PCR amplification. A new subtype of AmpC (chromosome) desoxyribonucleic acid ( DNA) was detected. Conclusion Acinetobacter baumannii is of high resistance to most antibacterial agents, and the mechanisms of the resistance are complex.