Objective To Study the effect of Con-saponin of Dioscoreae Nipponicae（CDN） on expressions of airway remodeling and to investigate the role of matrix metallo proteinase-9（MMP-9 ） and its tissue inhibitor （TIMP-1） in asthmatic mice. Methods Sixty SPF BALB/c mice were randomly divided into six group：normal group， model group， the Prednisone therapy group， low -dose CDN group， medium -dose CDN group， high -dose CDN group. The six groups except normal group were established by ovalbumin（OVA） sensitization．During the 18~55 days in the experiment， the normal and model groups were treated with normal saline， the Prednisone therapy group were treated with 10mg/kg of prednisone. At the same time， CDN groups were respectively treated with 20mg/kg、40mg/kg、80mg/kg of CDN. The pathological change of lung issues structure was studied under light microscopy and the expression of MMP-9 and TIMP-1 in lung tissues was detected by Western blotting. Results The pathological changes in lung tissue of asthmatic mice showed that CDN could improve the structure of the wall of the airway wall and epithelial， and reduce the infiltration of inflammatory cells. Compared with the normal group， The level of MMP-9 was significantly increased and TIMP-1 was significantly decreased in the model group（P<0.05）. Compared with the model group， the treatment groups significantly decreased the expression of MMP-9 （P<0.05） and significantly increased the expression of TIMP-1 （P<0.05）. The level of MMP-9 in all CDN groups was higher than the prednisone therapy group， and the level of TIMP-1 in all CDN groups lower in the prednisone therapy group. Conclusion CDN can improve the airway structure of asthmatic mice， and through inhibiting the expression of MMP-9 and increasing the expression of TIMP-1 to reduce the mice airway remodeling in asthma status.