Nonalcoholic steatohepatitis (NASH) is a common liver injury which will develop into advanced fibrosis and cirrhosis. This study was designed to identify the different serum metabolites of NASH hamsters and predict the diagnosis biomarkers for NASH. Golden hamsters were randomly divided into a control group that received a normal diet and a NASH group that received a high-fat diet (HFD). After 12 weeks of feeding, the body and liver weight of the hamsters were monitored. Serum biochemical parameters and liver histopathological changes were analyzed. Moreover, an untargeted metabolomics analysis based on a GCTOF/ MS system was performed to identify the serum differential metabolites between the NASH and control groups. The liver weight was increased in the NASH group, accompanied by significantly higher levels of serum TC, TG, ALT, AST, LDL-C, and lower HDL-C. HE, Masson, and oil red O staining showed the hepatocyte structure destroyed, lipid droplets accumulated, and fibers proliferated in the NASH group. Furthermore, 63 differential metabolites were identified by metabolomic analysis. Lipids and fatty acids were significantly up-regulated in the NASH group. The top 9 differential metabolites included cholesterol, methyl phosphate, taurine, alpha-tocopherol, aspartic acid, etc. Metabolites were mainly involved in amino acid metabolism (glycine, cysteine, taurine), spermine, fatty acid biosynthesis, urea cycle, bile acid metabolism pathways, etc. Conclusion: Metabonomics analysis identified 63 differential metabolites in the serum of NASH hamsters; among them, lipids and fatty acids had a key role and may be used as biomarkers for the early diagnosis of NASH.