Objective To explore the effectively of N -acetylcysteine effervescent tablets combined tiotropium bromide powders for inhalation in treatment of patients with acute exacerbation of chronic obstructive pulmonary disease. Methods 72 patients with acute exacerbation of chronic obstructive pulmonary disease were randomly divided into control group(36 cases)and treatment group(36 cases)according to random number table method.In treatment group,patients were given N -acetylcysteine effervescent tablets(600mg,2 times/d,oral)and tiotropium bromide powders for inhalation(18 μg,one time /d)for a month,and in the control group,patients were given tiotropium bromide powders for inhalation (18 μg,one time /d).Pulmonary function and clinical changed symptoms were observed as evaluation index before and after treatment in patients of the two groups Results The total effective rate were 61.1%,83.3% in the treatment group and control group respectively,there was a statistically significant difference (χ2 =4.430,P =0.035).Before the treatment,there was no significant differences between the two groups of patients with pulmonary function(P >0.05).After a month,pulmonary function of patients′FEV1 ,FVC and FEV1 /FVC in the treatment group were (1.9 ±0.6)L,(3.1 ±0.3)L and (67.9 ±8.4)% respectively,which in the control group were (1.6 ±0.5)L,(2.7 ±0.2)L and (59.3 ±7.4)%,there were significant differences(t =2.304,6.564,4.609, P =0.021,0.000,0.000).Conclusion N -acetylcysteine effervescent tablets combined with tiotropium bromide powders for inhalation can improve the clinical curative effect for patients with acute exacerbation of chronic obstructive pulmonary disease,which can be used to improve the patients'clinical symptoms and pulmonary function.