ObjectiveTo explore the meridian tropism of components in Bupleuri Radix （Chaihu， CH） based on the model of nonalcoholic steatohepatitis （NASH） and clarify the substance basis of the meridian tropism of CH in Xiaoyaosan （XYS） by means of principal component analysis. MethodEighty SPF male C57BL/6 mice were randomly assigned into 8 groups， with 10 mice in each group. Except that the blank group was fed with the methionine choline-sufficient （MCS） diet， the other mice were fed with methionine choline-deficient （MCD） diet for 4 weeks to establish the nonalcoholic steatohepatitis （NASH） model. After the established model was confirmed by hematoxylin-eosin （HE） staining， the mice were administrated with corresponding drugs by gavage once a day for 4 weeks. Specifically， the 8 groups were XYS group （2.874 g·kg^-1）， XYS-CH group （2.445 g·kg^-1）， XYS-CH+volatile oils （Vol， 0.163 mg·kg^-1） group， XYS-CH+polysaccharides （Pol， 24.067 mg·kg^-1） group， XYS-CH+flavones （Fla， 2.241 mg·kg^-1） group， and XYS-CH+saponins （Sap， 2.746 mg·kg^-1） group. The model group and the blank group were administrated with the same volume of normal saline. After the last administration， the mice were sacrificed for the collection of blood and liver tissue. The pathological changes of liver were observed by HE staining and oil red O staining. Enzyme linked immunosorbent assay （ELISA） kits were used to determine the levels of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， triglyceride （TG）， total cholesterol （TC）， high-density lipoprotein （HDL）， and low-density lipoprotein （LDL） in serum as well as malondialdehyde （MDA）， superoxide dismutase （SOD）， catalase （CAT）， and glutathione peroxidase （GSH-Px） in liver. SPSS Statistics 23 was used for principal component analysis and comprehensive evaluation to determine the substance basis of the meridian tropism of CH in NASH mice. ResultCompared with the blank control group， the modeling led to hepatocyte swelling， increased fat vacuoles， and appearance of inflammatory cells. Further， the modeling elevated the levels of ALT， AST， TG， TC， and LDL and lowered the HDL level in serum， and it increased the MDA level and decreased the SOD， CAT， and GSH-Px levels in liver. Compared with the model group， the administration of XYS and XYS-CH in combination with the components of CH alleviated the oxidative damage in liver （P<0.05）. The comprehensive score of the pharmacological efficacy was in a descending order as follows： XYS > XYS-CH+Sap > XYS-CH+Fla > XYS-CH+Pol > XYS-CH+Vol > XYS-CH. Among the chemical components of CH， Sap had the best effect. ConclusionSap lowers the blood lipid level， regulates the abnormal lipid metabolism， and alleviates the oxidative damage of liver， which is the substance basis for CH to exert the meridian tropism in liver.