Pulmonary fibrosis(PF)is a progressive,interstitial fibrotic lung disease characterized by persistent scar formation in the lung parenchyma,and a reduced quality of life and poor prognosis for patients.The pathogenesis of PF is unknown and there is a lack of effective therapeutic agents;however,animal models are currently the main tool used to explore the pathogenesis of the disease and to find effective therapeutic agents.PF can be induced by various factors and to different degrees according to known etiologies.Among these,bleomycin-induced models are widely used because of their reproducibility and the similarity between the fibrosis pathology and clinical conditions.The main induction method include intratracheal drip,intratracheal nebulization,tail vein injection,intraperitoneal injection,and transnasal inhalation,and these can be classified into single and multiple doses,according to the frequency of induction.Based on the relevant literature,the current review summarizes the characteristics of the bleomycin-induced PF model using different induction frequencies and method,to provide a basis for the application of this model.