Objective: To observe the effect of modified Xiongxie San on mRNA expressions of matrix metalloproteinases-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in lung tissue of cough variant asthma (CVA) model rat. Method: The 4-month old Wistar rats were randomly divided into the control group

the model group

the singulair group (1.2 mg·kg-1·d-1)

and the high-

medium-

low-dose modified Xiongxie San groups (8.64

4.32

2.16 mg·kg-1). The CVA model was induced in rats except the rats in the control group by intramuscular injecting of 4% OVA solution of 0.5 mL from the first day

intraperitoneal injecting 2% Al(OH)3 of 0.2 mL once daily

and inhaling 1%OVA solution for 2 minutes from the fourteenth day once every other one day for 7 times. All rats were administrated intragastrically with the corresponding medicines for continuous 15 days from the fourteenth day. The cough frequency was detected. The pulmonary pathology was observed by HE staining

inflammatory cells in bronchoalveolar lavage fluid(BALF) were observed by Wright's staining. The mRNA expressions of MMP-9 and TIMP-1 in rats' lung tissue were observed by RT-qPCR. Result: Compared with the normal group

the lung injury and inflammatory cell infiltration condition were serious

the cough frequency increased

the mRNA expressions of MMP-9 and TIMP-1 in lung tissue increased in the model group (P <0.01). Compared with the model group

the lung injury and inflammatory cell infiltration condition were improved

the cough frequency decreased

and mRNA expressions of MMP-9 and TIMP-1 in lung tissue decreased in all dose of Xiongxie San groups (P <0.01

P <0.05). Specially

the pulmonary pathology improvement had better result in the high-dose Xiongxie San group (P <0.01). Conclusion: Modifed Xiongxie San could inhibit airway remodeling of CVA

and the pharmacological mechanism may be related to reducing the increased mRNA expressions of MMP-9 and TIMP-1 in lung tissue.