To evaluate the curative effect of Shegan Mahuang Decoction on the cough variant asthma, and to observe the effects on improving cellular immune function and analyze the mechanism.Methods:A total of 60 cases of patients with cough variant asthma were included in research, and randomly divided into the control group and the observation group, with 30 cases in each group.The patients in the control group had oral Montelukast (10 mg/times, 1 time/day) and inhaled budesonide (300 μg/time, 2 times/d), rinse the mouth after inhalation.The observation group had Shegan Mahuang Decoction on the basis of treatment of the control group, with 200 mL decoction, warm-taken separately in the morning and evening, 1 agent/day.Both groups had 14 d continuous treatment.The cough symptom scores, pulmonary function, neutrophil count in induced sputum and Th1/ Th2 ratio changes of two groups before and after the treatment were compared.Results:1) Cough symptom scores of the patients in both the two groups decreased after treatment, and the descend range of the observation group was greater than that of the control group.The differences were statistically significant (P<0.05); 2) Pulmonary function index of the two groups improved after treatment, and each index of the observation group was superior to that of the control group (P<0.05); 3) Neutrophil percentage of induced sputum reduced in the patients of the two groups after treatment, and the observation group was superior to that of control group (P<0.05); 4) Proportional of Th1/Th2 increased in the patients of both the two groups after treatment, and the promotion of the observation group was more obvious.The differences were statistically significant (P<0.05).Conclusion:Shegan Mahuang Decoction can effectively treat cough variant asthma, and improve cell-mediated immunity function in the human body.