Abstract: Taking Auricularia auricula（L.ex Hook.） Underw mycelium cultured without carbon source as test material, the nontargeted metabonomic analysis of Auricularia auricula（L.ex Hook.） Underw mycelium was conducted by liquid chromatography mass spectrometry（LC-MS） technology.The effects of different carbon source treatments on the metabolites of Auricularia auricula（L.ex Hook.） Underw mycelium were studied, in order to provide reference for the mechanism of Auricularia auricula（L.ex Hook.） Underw mycelium degradation of carbon source.The results showed that based on principal component analysis（PCA）,there were significant differences between samples; a total of 588 metabolites were identified based on the results of partial least squares discriminant analysis.A total of 66differential metabolites were obtained by screening significant metabolites（P＜0.05）,including amino acids and their derivatives,unsaturated fat acids,organic acids and their derivatives,organic compounds,phenols,lipids,terpenes and other compounds.Based on KEGG pathway analysis,differential metabolites were annotated into 21metabolic pathways,of which7were significantly enriched（P＜0.05）.