Objective: To study the therapeutic effects of panax notoginside (PN) and methylprednisolone (MP) on pulmonary fibrosis in rats. Methods: Bleomycin was introduced into the bronchial tree of 75 Wistar male rats through a tracheal incision to establish a rat model of pulmonary fibrosis (PF). The rats were equally divided into 3 groups: PF group,PN treated group and MP treated group. Five rats of each group were killed 1, 3, 7, 14 and 28 d after the administration of bleomycin and the specimens of lung tissue and plasma were collected for the determination of content of collagen Ⅰ and Ⅲwith immunohistochemical method and the level of MIP-1α and MCP-1 with ELIZA. Results: The severity of PF, the content of collagen Ⅰ and Ⅲ and the level of MIP- 1 α and MCP- 1 were significantly decreased in PN and MP treated groups than in PF group ( P ＜ 0.05). Conclusion: PN and MP are effective to control the development of PF induced with bleomycin in rats.