Background: Previous studies have shown the insecticidal efficacy of ginsenosides. In the present study,we aimed to investigate the metabolic mechanism related to the inhibitory effect of panaxadiol saponins(PDSs) against the Asian corn borer Ostrinia furnacalis (Guenee). Methods: Third instar larvae of O. furnacalis were fed normal diets with different concentrations of PDSsfor 4 days. The consumption index, relative growth rate, approximate digestibility, and conversion ofingested and digested food were recorded. A targeted gas chromatographyemass spectrometry assaywas performed to detect the profiles of amino acids, fatty acids, and carbohydrates in larvae ofO. furnacalis. In addition, the activity of detoxification-related enzymes was determined. Results and Conclusions: PDSs decreased the consumption index, relative growth rate, approximate digestibility,and conversion of ingested and digested food in the 3rd instar larvae of O. furnacalis in a dosedependentmanner. PDSs decreased 15 free amino acids, 16 free fatty acids, and 5 carbohydrates andincreased the levels of palmitoleic acid, palmitic acid, and 9-octadecenoic acid in the 3rd instar larvae. The activity of detoxification-related enzymes, such as acetylcholinesterase, glutathione S-transferase,cytochrome P450, carboxylesterase, trehalase, acid phosphatase, and alkaline phosphatase, was reducedin a dose-dependent manner in the 3rd instar larvae exposed to PDSs. These data confirmed theinhibitory effect of PDSs against growth, food utilization, and detoxification in the 3rd instar larvae ofO. furnacalis and the potential for using PDSs as an efficient tool for insect pest management forO. furnacalis larvae.