Objective:To evaluate the effects of Kechuan Liuwei Mixture on the lung function and life quality of severe COPD patients with syndrome of deficiency of kidney yang. Methods 108 patients with severe COPD in stabilization period were randomly divided into the control group(36 cases)and the treatment group(72 cases). The control group was treated with Seretide inhalation at conventional dose,the treatment group was treated with Kechuan Liuwei Mixture combined with Seretide inhalation at small dose,with a course of 3 months. The clinical efficacy was observed,and the changes of lung function,6min walking distance,St. George’s respiratory questionnaire score and life quality score were compared before and after treatment.  Results:The total effective rate was 84.72% in the treatment group and 58.33% in the control group,the clinical efficacy of the treatment was better than that of the control group(P,<,0.01). After treatment,the FEV,1,% in both groups was increased compared with the treatment before(P,<,0.05),but there was no statistically significant difference between the two groups(P,>,0.05). After treatment,the 6min walking distance and the scores of St. George’s respiratory questionnaire and life quality were increased in both group compared with the treatment before(P,<,0.01),and the increase in the treatment group were more significant than those in the control group(P,<,0.05).  Conclusion: Kechuan Liuwei Mixture can enhance the clinical efficacy of COPD and improve the lung function and life quality of patients.