Abstract： BACKGROUND: Allergic airway inflammation (AAI) is the pathological basis of pathogenesis of asthma. Manghua decoction, from Zhang Zhongjing's "On cold damage", is the basic recipe for treating asthma, its addminus recipe is widely used in clinic now.OBJECTIVE: To investigate the effect of mahuang decoction on allergic airway inflammation in asthmatic mouse.DESIGN: Randomized controlled observation SETTING: Staff Room of Internal Medicine, Department of Clinical Medicine, Guangdong University of Pharmacy.MATERIALS: The experiment was performed in the Animal Laboratory of Guangdong College of Pharmacy and Laboratory of Pathology, Guangdong University of Pharmacy from March 2003 to February 2004. Totally 36 mice were recruited.METHODS: Mice were randomly divided into normal control group, asthma group and treatment group, with 12 in each one. The mice in the control group were given intraperitoneal injection of 0.2 mL of normal saline on day 1,7,14 and 21 separately. From 28th day, the mice were given intragastric administration of normal saline of 0.5 mL for 60 minutes followed by water spray(only normal saline ) for 30 minutes , for consecutive 7 days.The mice in the asthma group were given intraperitoneal injection of normal saline of 0.2 mL containing egg albumin (10 μg) and aluminium hydroxide (20 mg) on day 1, 7, 14 and 21 separately. From 28th day, the mice were given intragastric administration of normal saline of 0.5 mL for 60 minutes followed by water spray (normal saline containing egg albumin of 50 g/L) for 30 minutes, for consecutive 7 days. Sensitization and stimulati on of the mice in the treatment group were the same as that in the asthma group. Intragastric administration of mahuang decoction of 0.5 mL was performed 60 minutes before spray. The procedure was conducted for consecutive 7 days. The pathologic change and the lung tissues expression of interleukin-4 (IL-4) and interferon-γ (IFN-γ) of the mice in each group were analyzed with hamatoxylin-eosin staining and immunohistochemical staining.MAIN OUTCOME MEASURES: Comparison of airway infiltration cells and lung tissue IFN-γand IL-4 of the mice in each group RESULTS: Totally 36 mice entered the stage of result analysis with no loss in the midway. ① Inflammation of the mice relieved obviously in the treatment group than in the asthma group, and the number of the inflammatory cells in or around bronchi of the mice was significantly less in the treatment group than in the asthma group . ② The number of IL-4 and IFN-γ was significantly increased in the asthma group than in the normal control group, among which , the number of IL-4 was more significant, and the ratio of IFN-γ / IL-4 was decreased. However, the number of IL-4 on the treatment group was significantly decreased, and that of IFN-γ was remarkably increased , and the ratio of IFN-γ / IL-4 was significantly increased as compared with that in the asthma group.CONCLUSION: Asthmatic mice might exist the disequilibrium of Th1/Th2 subgroup. Mahuang decoction can improve the inflammation of bronchus,regulate the ratio of Th1/Th2, which might be one of the mechanism for treatment of asthma.