Objective Metabolomics was used to analyze the changes of metabolites in the plasma of Fenpropathrin-contaminated rats to find potential biomarkers for forensic identification of Fenpropathrin poisoning.Methods SD rats in the two experimental groups were given 20.5 mg/kg and 41 mg/kg doses of fenpropathrin respectively by gavage.The rats in the control group were given equivalent volume of normal saline.The angular vein blood of rats was collected 24 hours after gavage,and endogenous small molecule metabolites in plasma were investigated by ultra-performance liquid chromatography-time-of-flight mass spectrometry(UPLC-TOF-MS).The data was processed by SIMCA14.1.The differential metabolites in plasma of fenpropathrin-infected rats were screened out according to the Variable Importance in Projection(VIP)and p<0.05 in the OPLS-DA model.Finally,the pathways were analyzed.Results There were significant differences in plasma metabolite levels between the control group and the experimental group,and 17 biomarkers were selected to identify whether the rats had received fenpropathrin,which mainly affected purine metabolism,Alanine,aspartate and glutamate metabolism,arginine biosynthesis,biosynthesis of unsaturated fatty acids and pyrimidine metabolism.Conclusion Fenpropathrin can change the composition of metabolites in rats,and the differential markers screened can provide supportive forensic evidence for cases related to deltamethrin poisoning.