Objective To investigate the effects of Xuelian on paraquat-induced pulmonary fibrosis in rats and its possible mechanism.Methods 30 Wistar rats were randomly divided into three groups(12 in B and 12 in T group,6 in N group),physiological saline group(N)(lavage),paraquat group(B)(intragastric administration with paraquat),and Xuelian group(T)(peritoneal injection with paraquat and Xuelian).The rats were sacrificed at 14 and 28 days after the treatment.The lungs were harvested for histopathologic HE staining.The expression of HYP in the lungs was examined.The levels of transforming growth factor-β1(TGF-β1) in tissue homogenate were assayed by enzyme-linked immunosorbent analysis.Results In paraquat group,the pulmonary fibrosis was apparent.In Xuelian group,however,the pulmonary fibrosis was much milder.The expression of HYP in lungs was reduced.Overexpression of TGF-β1 on the day 28 induced by paraquat was also suppressed significantly by Xuelian.Conclusion The pulmonary fibrosis induced by paraquat can be inhibited by Xuelian.The inhibitory effect of Xuelian may be ascribed to the reduction of TGF-β1 partly.