OBJECTIVETo observe the effect of Xiaochuanping powder (XP), a traditional Chinese prescription for the treatment of cough and asthma, on serum concentrations of eosinophil cationic protein (ECP), tumor necrosis factor (TNF)-α, and interleukin (IL)-4, eosinophil counts, as well as expression of matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinase (TIMP)-1 in the lung tissues of asthmatic rats. METHODSSixty clean-grade Sprague–Dawley rats were divided randomly into six groups: normal control (NC), asthma model, Guilong Kechuanning (GK) group, as well as high-, intermediate-, and low-dose XP groups. Rats were sensitized with ovalbumin (OVA) to trigger asthma. Serum concentrations of ECP, TNF-α and IL-4, eosinophil counts, as well as expression of MMP-9 and TIMP-1 in lung tissues were evaluated using an immunofluorescence method. mRNA expression of MMP-9 and TIMP-1 was determined using real-time quantitative polymerase chain reaction. RESULTSCompared with the asthma-model group, serum concentrations of ECP, TNF-α, and IL-4, and eosinophil counts decreased significantly in the high- and intermediate-dose XP groups and GK group (all P < 0.01). Protein expression of MMP-9 and TIMP-1 decreased significantly in the high- and intermediate-dose XP groups and GK group (all P < 0.01). Transcription of MMP-9 and TIMP-1 mRNA and the ratio of expression of MMP-9: TIMP-1 in lung tissue were significantly lower (P < 0.01). CONCLUSIONXP can reduce TNF-α secretion, suppress the infiltration / activation of eosinophils, reduce serum concentrations of ECP and IL-4, reduce the protein and mRNA expression of MMP-9 and TIMP-1 in lung tissue, and regulate the balance between expression of MMP-9 and TIMP-1. In these ways, XP alleviated the inflammation and remodeling of the airways.