The present invention relates to an extract isolated from Sophorae Radix useful for prevention and treatment of respiratory diseases. More specifically, the present invention relates to a pharmaceutical drug comprising the Sophorae Radix extract having excellent effects of inhibiting airway contraction, respiratory infections, 5-lipoxygenase activity, phosphodiesterase 4 activity, airway hyper-responsiveness and airway remodeling； antagonistic activity against leukotriene D 4 ； and an antitussive effect, thus being useful for prevention and treatment of respiratory diseases such as asthma, acute or chronic bronchitis, allergic rhinitis, acute upper respiratory infections and acute lower respiratory infections, and the like.本發明關於一種從山豆根(Sophorae_Subprostratae Radix)單離出的萃出物，可供用於預防及治療呼吸道疾病。詳言之，本發明關於一種藥物，其包含山豆根萃出物，可供用於預防及治療諸如氣喘、急性或慢性支氣管炎、過敏性鼻炎、急性上呼吸道感染及急性下呼吸道感染等呼吸道疾病。
