Background : Nowadays asthma is considered to be an inflamatory disease characterized by airborne hyper-responsiveness and pulmonary eosinophilia. Objective : We aimed to identify the effects of Sochongryongtang on blood eosinophil, serum IgE and T lympocyte subpopulation in asthmatic patients. Material and Methods : The subjects consisted of fifteen patients with asthma who had been treated with Sochongryongtang for two weeks from February 2001 through June 2001. Sochongryongtang is herbal decoction which has been used for the traditional therapeutic agent of asthma. Results : The blood eosinophil and serum IgE in a normal controlled group. However, the T lympocyte subpopulation in asthmatic patients was not significantly different from the T lympocyte subpopulation in a normal group. The patients were treated with Sochongryongtang for two weeks. No significant difference in the blood eosinophil, serum IgE and T Iympocyte in the sub population. After treatment with Sochongryongtang for two weeks, FEV 1 increased significantly over 0.5 points out of total scores. Conclusion : This study shows that Sochongryongtang has effects on improvement of pulmonary function and quality of life in asthmatic patients. However, the patients who were treated with Sochongryongtang for two weeks showed no significant difference in the blood eosinophil, serum IgE and T lympocyte subpopulation. Further long-term studies must be made on a large number of asthmatic patients.