ObjectiveTo realize the antimicrobial resistance of Acinetobacter baumannii (Ab), and effect of  ethylenediaminetetra5 acetic  acid （EDTA ）,minocycline and salicylic acid  on  its biofilm formation. MethodsAntimicrobial susceptibilities of 72 strains of Ab were detected with KirbyBauer method; Minimal inhibitory concentrations of EDTA, minocycline and salicylic acid  on Ab were determined by broth microdilution method; The biofilm formation rates of different drugresistant Ab and the effect of different concentrations of EDTA, minocycline and salicylic acid on biofilm formation and mature biofilm were determined by adhesion test.ResultsThe MIC90 of EDTA， minocycline and salicylic acid  for Ab was 200 mg/L,4 mg/L and 600 mg/L, respectively. The biofilmpositive rates in sensitive Ab （SAb）strains, multidrug resistant (MDRAb) strains  and  pandrug resistant (PDRAb) strains was 22.22%, 83.33% and 76.67%, respectively.  EDTA  with concentration of 250 mg/L and 500 mg/L, minocyline 4 mg/L and 8 mg/L,and salicylic acid 1 000 mg/L  can inhibit the mature biofilm.ConclusionThere are a high biofilmpositive rate in multidrug and pandrug resistant Ab . EDTA, minocycline and salicylic acid  can inhibit the formation of biofilm.