OBJECTIVE： To provide reference for rational drug use in clinic and nosocomial infection control. METHODS： Acinetobacter baumannii（AB） were collected from our hospital during Jan. 2014-Jun. 2017. Drug sensitivity tests were conducted by using K-B method and MIC method. Drug-resistance genes of multidrug-resistant Acinetobacter baumannii（MDR-AB）were amplified by PCR， and compared with GenBank database by using Blast comparison. RESULTS： A total of 1 758 strains of AB were detected， and mainly came from sputum and throat swab （65.24％）， followed by urine （18.49％）. These infected patients were mainly distributed in the departments of ICU （38.51％） and respiratory medicine （24.00％）， respectively. Drug resistance of clinical isolated AB to most commonly used antibiotics were more than 40％， such as compound sulfamethoxazole， piperacillin sodium and tazobactam sodium， gentamicin， cefepime， levofloxacin， minocycline， imipenem， etc.； it had increased year after year. Drug resistance to colistin was lower than 5％ and decreased year by year. A total of 673 strains of MDR-AB were detected， and detection rates were 22.77％，29.82％，52.09％，54.33％， respectively. Among 110 strains of MDR-AB， detection rates of TEM， AmpC， IMP， VIM， OXA-23， OXA-24， OXA-51， aac（6′ ）-Ⅰ， aac（3）-Ⅰ， ant（3″ ）-Ⅰ， anmA， gyrA， parC gene were 97.27％， 91.82％， 49.09％， 12.73％、90.91％， 12.73％， 98.18％， 34.55％， 60.91％， 89.09％， 87.27％， 77.27％， 82.73％， respectively. Results of Blast comparison showed that point mutation occurred in 83rd and 121st base of gyrA gene， 144th base of parC gene. CONCLUSIONS： AB mainly come from sputum and throat swab specimens in our hospital， and infected patients are mainly distributed in the departments of ICU and respiratory medicine. Drug resistance is serious， and the detection rate of MDR-AB is increased year by year. Main genes of multidrug-resistant strains mainly include TEM， AmpC， OXA-23， OXA-51， ant（3″ ）-Ⅰ， anmA， etc.， and mutation of gyrA and parC gene are found. It is necessary to strengthen the management of classification use of antibiotics and strengthen the monitoring of AB drug resistance. According to the results of drug sensitivity test， antibiotics are selected rationally to prevent or delay planting and cross transmission of AB-resistant strain.