The aim of this study was to investigate the mechanism of the total saponins of ,Panax japonicus, on improving the lipid metabolism in HepG2 cells based on cell metabolomics. The HepG2 lipid deposition model was established with a 1 mmol/L free fatty acid mixture（oleic and palmitic acid at the proportion of 2∶1）. Oil red O staining and triglyceride analysis were carried out after 24 h of treatment with the total saponins of ,Panax japonicus,（50 mg/L）. Total metabolites in HepG2 cells were extracted according to the improved Bligh-Dyer method and were further separated into polar and nonpolar fractions. Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry（UPLC-Q/TOF MS） was used to detect and identify the metabolites. The Progenesis QI software was used to pre-process the data，such as baseline correction，peak alignment，peak recognition，peak extraction and peak normalization. The principal component analysis，orthogonal partial least squares discriminant analysis and volcano map analysis were used to screen the differential metabolites. Metabolic pathways were enriched by the MetaboAnalyst software. The results showed that the total saponins of ,Panax japonicas, could significantly improve the lipid accumulation induced by oleic and palmitic acid in HepG 2 cells. 34 differential metabolites were identified in polar fraction，mainly including fatty acids and amino acids. 28 differential metabolites were identified from the nonpolar fraction，mainly including phosphatidylcholines，phosphatidyl ethanolamines and ceramides. These differential metabolites tended to return to normal levels after treatment with the total saponins of ,Panax japonicus,. Differential metabolites are mainly involved in three metabolic pathways，including sphingolipid metabolism，glycerol phospholipid metabolism and unsaturated fatty acid synthesis. This study elaborated the possible mechanism of the total saponins of ,Panax japonicus, on ameliorating lipid accumulation induced by oleic and palmitic acid in HepG2 cells from the perspective of cell metabolism，which was closely related to the regulation of sphingolipid metabolism，glycerolipid metabolism，fatty acid metabolism and inflammatory response. This study provided a reference for the lipid-lowering effect study of the total saponins of ,Panax japonicus,in,vivo,.