〔Abstract〕 Abstract Objective To explore the differential lipid metabolites in the plasma of mice with idiopathic pulmonary fibrosis (IPF) . Methods Thirty SPF C57BL/6 male mice were randomly divided into 2 groups with 15 mice in each group . The experimental groups were divided into control group and bleomycin (BLM) group . The model of idiopathic pulmonary fibrosis was induced by one-time intratracheal infusion of BLM ( 1 mg/kg) . Hematoxylin-eo- sin (HE) staining was used to observe the lung histopathology . The collagen fiber deposition in lung tissue was ob- served by Sirius red staining. The differential lipid metabolites in plasma of IPF mice were screened and enriched by lipidomics . Results HE staining showed that the pulmonary tissue structure was disordered , alveolar septum was broken and alveolar wall was destroyed in BLM group . Sirius red staining showed a large amount of collagen fi- ber deposition in the lung interstitium of BLM group . The results of lipidomics analysis showed that the lipid metab- olism profile of BLM group changed , 15 differential lipid metabolites were screened out , of which 11 differential lipid metabolites were up-regulated , and 4 differential lipid metabolites were down-regulated , mainly concentrated in Glycerophosphoglycerophosphates , Glycerophosphocholines , Steroid lactones , etc . Conclusion The lipid me- tabolism profile of BLM group mice changes , differential lipid metabolites such as phosphoglycolate phosphatase (PGP)(18:0/18:0) , PGP( i-12:0/i-24:0) , PGP( i-13:0/a-25:0) , and phosphatidylcholine ( PC) (18:0/14 : 0) , PC(18:3/16:0) , lysophosphatidylcholine (LPC)(16:1) , and LPC(18:3) may play an important role in the progression of IPF . These findings provide a new reference for further study of the molecular mechanism of IPF , and also provide a potential new target for clinical treatment.