Abstract： Objective To explore the clinical features,risk factors and the sensitivity to antibiotics of lower respiratory tract acinetobacterial infection.Methods The clinical data,results of sputum bacterial culture and drug sensitivity of the 72 cases with lower respiratory tract acinetobacterial infection were netrospectively reviewed.Results 53 cases(73.6%)were elder than 60 years old,69 cases(95.8%)had basic diseases,and 59 cases(81.9%)were nosocomial infection.Risk factors included basic diseases,lower immune function,all kinds of invasive operations,aerosol inhalation,unreasonable usage of antibiotics.Drug sensitivity test showed that the drugs which sensitive to acinetobacter was upper than 50% included Imipenen,Levofloxacin,Cefooerazone/sulbactum and Amikacin.Conclusion The patients who sufferred from lower respiratory tract acinetobacterial infection usually are elder than 60 years old,and have basic diseases.Most of this kind of infection is nosocomial infection.Because of severe clinical symptom and high drug resistant rate,the prognosis is poor.Reasonable selection of sensitive antibiotics is important.