Objective:To investigate the effects of lung lavage by bronchoscopy in the treatment of acute exacerbation of chronic obstructive pulmonary disease(AECOPD)and its safty.Methods:85 patients with AECOPD were recruited on general wards and randomly assigned to standard medical treatment group(group A,n=42)or early administration of lung lavage Plus standard medical treatment group(group B,n=43).Lung lavage was performed in the group B with Lung lavage fluid on the three days prior to admission.Arterial blood gases,respiratory function and comprehensive assesment of clinical data were observed before and on the 5th day after treatment.Results:The levels of FEV1,PaO2,PaCO2 and clinical symptoms were markedly improved after A.B group treatment.Group A and B had statistically significant difference in the two group(P<0.05).Conclusions:Lung lavage by bronchoscopy was a safe and effectual way and easy to popularize in the treatment of AECOPD.