Objective To observe the expression of TGF-β/Smad and Wnt/β-catenin signaling pathway-related genes in the lung tissue and explore the function and interaction of the two pathways in bleomycin-induced pulmonary fibrosis in rats.Methods Thirty-six male Wistar rats were randomly divided into two groups, the control group (n=18) and model group (n=18). The rats were intratracheally injected with saline and bleomycin solutions, and killed on the 14th, 21st and 28th days after operation, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of HYP and IL-1β in the lung tissues. Real-time PCR was used to detect the expression of IL-1β, Col-I, TGF-β1, Smad3, α-SMA, Wnt1, β-catenin, and LEF-1mRNA in the lung tissues. Histopathological examination of the lung tissues was done with hematoxylin-eosin (HE) and Masson staining. Results (1) Compared with the normal group, the lung indexes were significantly increased during the 14 to 28 days after bleomycin administration (P<0.01). The pathological changes were in accordance with pulmonary fibrosis, and the blue collagens by Masson staining were gradually increased in the pulmonary interstitium at 14 to 28 days after model building. (2) Compared with the normal group, the IL-1β content and the expression of IL-1β were significantly increased on the 14th day after bleomycin administration (P<0.01) and then declined gradually, and on the 28 day the expression of IL-1β was near to the normal level (P >0.05). (3) At 14 to 28 days after operation, the content of hydroxyproline and the expression of Col-I were increased successively, and were significantly higher than those in the control group (P<0.01). (4) Compared with the normal group, the expression of TGF-β1, Smad3, α-SMA,Wnt 1, β-catenin, LEF-l were significantly increased after operation (P<0.01)，and there was a significant positive correlation between them. Conclusions The expression of TGF-β/Smad and Wnt/β-catenin pathway-related genes are increased in bleomycin-induced pulmonary fibrosis in rats. The two pathways may promote the process of fibrosis and there may be some relationship between them.