Objectives : Based on the changes of quality of life and pulmonary function test, we aimed to identify the effects and side-effects of Gamichuongsangboha-tang and in asthmatic patients. Methods : The subjects consisted of 30 patients with asthma who were treated with Gamichuongsangboha-tang extract for four weeks. Gamichuongsangboha-tang extract is the extracted powder form of the modified herbal decoction Chuongsangboha-whan, which has been used as the traditional therapeutic agent for asthma. Pulmonary function test (PFT) was checked before and after 4 weeks of treatment. Quality of Life QuestionnaireQ for Adult Korean Asthmatics (QLQAKA) was checked before and after 2 and 4 weeks of treatment. Unpleasant symptoms were checked in all patients at 2 weeks and 4 weeks from the beginning of treatment. Results : Treatment with Gamichuongsangboha-tang extract for four weeks resulted in significant increase in $FEV_{1.0}%$, PEFR%, and QLQAKA. The total efficacy rate of QLQAKA in the patient group was 53.3% after 4 weeks. The QLQAKA of the step 2, step 3, and step 4 groups (n=18, 55.6%) classified by global initiative for asthma (GINA) consistently increased, and significant improvement of QLQAKA occurred in the step3 group. In the step 4 group, FEV1.0%, and PEFR% were significantly increased. A total of 15 patients experienced unpleasant symptoms during the first 2 weeks of treatment, but these symptoms disappeared in all but 2 cases with no need of further treatment during the 2nd 2-week period. Conclusions : This study shows that Gamichuongsangboha-tang extract has effects on improvement of pulmonary function and quality of life, especially in persistent symptomatic asthmatics. Obviously further study concerning all these is still necessary.