Objective:To observe the effect of Yunpi-Xiefei-Huatan Decoction on airway mucus hypersecretion of asthmatic rats and its regulation on epidermal growth factor receptor (EGFR) / mucin 5AC (MUC5AC) signal pathway. Methods:Seventy SD rats were randomly divided into normal group, model group, high dose group, medium dose group, low dose group, western medicine group and combined group, with 10 rats in each group. Except the normal group, the other groups were sensitized with 1 ml ovalbumin and aluminum hydroxide mixture to establish the asthma rat model. On the 16th day of the experiment, the high, medium and low dose groups were given Yunpi-Xiefei-Huatan Decoction of 40, 20, 10 g/kg, respectively, the western medicine group was given carboxymethylstein tablets of 150 mg/kg, and the combined group was given Yunpi-Xiefei-Huatan Decoction of 20 g/kg and carboxymethylstein tablets of 150 mg/kg, once a day, for 4 weeks. The levels of tumor necrosis factor (TNF-α) and interleukin-13 (IL-13) in serum of rats were detected by Enzyme-linked Immunosorbent Assay (ELISA), the total number and classification of leukocytes in BALF were observed by Wright Giemsa staining, the pathological changes of lung tissue were observed by glycogen staining (PAS). The protein expression of epidermal growth factor receptor (EGFR) and MUC5AC (MUC5AC) were detected by Western blotting, and the mRNA expression of EGFR and MUC5AC was detected by Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). Results:Compared with the model group, the level of IL-13 and TNF-α in the high, medium and low dose groups of traditional Chinese medicine, western medicine group and combined group was significantly decreased ( P<0.05). The levels of WBC, eosinophils and neutrophils in rat alveolar lavage fluid were significantly decreased ( P<0.05). The expression of EGFR (0.466 ± 0.023, 0.354 ± 0.047, 0.667 ± 0.066, 0.553 ± 0.065, 0.290 ± 0.033 vs. 0.782 ± 0.047) and MUC5AC (0.424 ± 0.022, 0.313 ± 0.033, 0.603 ± 0.051, 0.495 ± 0.041, 0.243 ± 0.024 vs. 0.806 ± 0.090) significantly decreased ( P<0.05), the m RNA expression of EGFR (2.302 ± 0.321, 2.549 ± 0.623, 3.084 ± 0.453, 2.585 ± 0.314, 1.810 ± 0.379 vs. 4.101 ± 0.567), MUC5AC (3.243 ± 0.742, 3.283 ± 1.064, 4.419 ± 0.572, 3.817 ± 0.637, 2.469 ± 0.424 vs. 5.840 ± 0.661) in the high, medium and low dose groups, western medicine group and combined group was significantly decreased ( P<0.05). Conclusion:Yunpi-Xiefei-Huatan Decoction ccould inhibit asthma, and its mechanism mightbe related to the EGFR/MUC5AC signaling pathway.