Abstract: Objective: To observe the clinical efficacy of the ancient formula Xiebai Wendan Decoction in the treatment of cough variant asthma(CVA) with phlegm-dampness accumulation in the lung in children. Methods: A total of 72 children with CVA phlegm-dampness accumulation in the lung were randomly divided into the observation group and control group(36 cases in each group).The control group was treated with oral montelukast sodium chewable tablets.The observation group was treated with oral administration of Xiebai Wendan Decoction combined with montelukast sodium chewable tablets.Both groups were treated for 4 weeks.The clinical efficacy,traditional Chinese medicine syndrome scores,pulmonary function indicators and serum IgE levels between two groups were compared.The recurrence situations in two groups were statistically analyzed after 3 months of drug withdrawal. Results: The total effective rate in the observation group was 91.67%,which was significantly higher than that in the control group (77.78%) (P<0.05).After treatment,the traditional Chinese medicine syndrome scores of the main symptoms in two groups were lower than those before treatment(P<0.05),and those in the observation group were lower than those in control group(P<0.05 to P<0.01).The pulmonary function indicators in two groups increased compared with those before treatment(P<0.05),and the serum IgE level decreased(P<0.05).Moreover,the pulmonary function indicators in the observation group were significantly better than those in control group,and the IgE level was significantly lower than that in control group(P<0.01).The recurrence rate in the observation group was 6.06%(2/33),which was significantly lower than that in control group(32.14%) (9/28) (P<0.01). Conclusions: The combination of Xiebai Wendan Decoction and montelukast sodium has a remarkable therapeutic effect on children with CVA and phlegm-dampness accumulation in the lung.It can improve the traditional Chinese medicine syndromes and children's lung function,reduce the serum IgE levels,and effectively lower the recurrence rate.