In this study, we report that astragalus extract inhibits airway remodeling in a mouse asthma model and regulates the TGF-β1/Smad signaling pathway in ovalbumin-sensitized mice, providing a novel mechanism for the astragalus extract inhibitory effect on airway remodeling in animal models of asthma. The gene discussed is TGFB1; the disease is asthma.