Background : Nowadays asthma is considered to be an inflammatory disease characterized by airway hyperresponsiveness and pulmonary eosinophilia. Production of cytokines by bronchial epithelial cells may contribution to the local accumulation of inflammatory cells in patients with bronchial asthma. Chungsangboha-tang is the herbal treatment of choice in persistent asthma patients. It has been recognized that cessation of treatment with Chungsangboha-tang evokes a recurrence of symptoms in patients with controlled asthma. This study was designed to evaluate the long-term effect of Chungsangboha-tang. Materials and Methods : The subjects consisted of 24 patients with asthma who had been treated with Chungsangboha-tang for four weeks. Chungsangboha-tang is an herbal decoction which has been used as the traditional therapeutic agent for asthma. PFT, QLQAKA, blood eosinophils, serum IgE, Serum IL-4, IL-5, $IFN-{gamma}$ were checked before treatment, before withdrawal and 3 months after cessation of treatment with Chungsangboha-tang. Results : Treatment with Chungsangboha-tang for four weeks resulted in significant increase in FEV1.0%, PEFR%, and QLQAKA. The patients were treated with Chungsangboha-tang for four weeks with no significant difference in the blood eosinophils, serum IgE, IL-4 and IL-5. The serum $IFN-{gamma}$ in asthmatic patients decreased significantly after 4 weeks of treatment. Discontinuation of treatment with Chungsangboha-tang resulted in significant drops in QLQAKA. Others measures in asthmatic patients 3 months after discontinuation of treatment with Chungsangboha-tang showed no significant difference. Conclusion : This study demonstrates that asthma can be exacerbated by discontinuation of treatment with Chungsangboha-tang in patients with asthma. Obviously further research concerning this is still necessary.