Abstract:To study the effect of inonotus obliquus polysaccharides （IOP） on endogenous metabolites in the liver tissue of hyperlipidemic rats，so as to explore the hypolipidemic mechanism of IOP. The hyperlipidemic rat model was induced by a high fat diet，and the related index contents in serum were detected. Combined with bioinformatics analysis，the data of mass spectrometry were interpreted by high-resolution and high-performance liquid chromatography-tandem mass spectrometer （HPLC-MS/MS） Triple TOF 5600 on positive and negative ion modes. The differential metabolites of IOP on the liver of hyperlipidemic rats were screened，and the possible metabolic pathways involved were analyzed. Results：the body weight of the rats in the MG group increased rapidly，and the growth trend of body weight in the PC group was similar to that in the IOP group.The results of serum biochemical indexes showed that compared with the MG group，the IOP significantly decreased the levels of TC，TG，and LDL-C and increased the level of HDL-C in the serum of rats. The results of liver metabonomics showed that compared with the MG group，16 metabolites，such as deoxycholic acid，17-hydroxylinolenic acid，and 12，13-glycerone，in the IOP group changed significantly. The metabolic pathways involved riboflavin metabolism，linoleic acid metabolism，unsaturated fatty acid biosynthesis，and primary bile acid biosynthesis. Metabonomics revealed that IOP had a certain intervention effect on hyperlipidemia rats，which may be related to riboflavin metabolism，linoleic acid metabolism，fatty acid biosynthesis，and bile acid biosynthesis.