Abstract: To explore the metabolites differences of grilled fish in different packages, liquid chromatography-tandem mass spectrometry was used to analyze and compare the metabolite profile of prefabricated grilled fish in tray packaging, vacuum packaging and modified atmosphere packaging through non-targeted metabolomics. The results showed that 318 metabolites were identified under secondary mass spectrometry information in the prefabricated grilled fish with different packaging. In this study, 47 differential metabolites were identified, including 10 fatty acids, 10 nucleotides, 9 amino acids, 7 organic acids and derivatives, 3 benzene and derivatives, 2 alcohol amines, and 6 unconfirmed metabolites, based on the variable importance projection value (VIP, VIP>1) and P<0.05 of the orthogonal partial least squares discriminant analysis model. Clustering heat map analysis of the relative content of 47 different metabolites was performed and the results showed differences in the relative content of metabolites in three types of packages. The relative contents of multiple flavor amino acids and adenosine monophosphate (AMP) were significantly higher in the modified atmosphere packaging than in the conventional vacuum package and tray package. The results revealed that modified atmosphere packaging effectively preserved the umami flavor of grilled fish, offering a basis for the development of novel and effective packaging for grilled fish.