In summary, the result of our study concluded that YYYQ could alleviate the severity of alveolitis and fibrosis on BLM-induced pulmonary fibrosis in rats, inhibit the mRNA expression of TGF-β1 and its receptors, Smad3, α-SMA, and CTGF, enhance mRNA expression of Smad7 and E-cadherin, and reduce the mRNA expression of collagen such as laminin, collagen I, and hydroxyproline, but the effect on interleukin 18 was not obvious. This evidence concerns the gene CDH1 and hypersensitivity pneumonitis.