Abstract: In order to study the difference of Carboxymethyl-chitosan(CMCS)-induced resistant metabolites in postharvest grapefruit fruits. In this study, grapefruit fruits were used as test materials, and grapefruit was induced by 1.5% CMCS and sterile water(CK) for 24 h, respectively. The differences of metabolites in grapefruit fruits were analyzed by non-targeted metabolomics. The results showed that a total of 92 differential metabolites were obtained after CMCS induced grapefruit for 24 h, of which 36 were up-regulated and 56 were down-regulated. The KEGG pathway annotation results showed that the differential metabolites were significantly(P < 0.05) enriched into 21 pathways, mainly involved in amino acid and phenylpropanoid metabolism. Further screening found that the expression levels of L−Glutamine, L−Glutamic acid, L−Asparagine, Arginine, Tyramine, Malonic acid, Shikimic acid, D-erythro-3-Methylmalate, trans-Cinnamate and Coumarin changed significantly, and were significantly(P < 0.05) higher than CK. In addition, the related differential metabolites and key resistance differential genes(HSP17.4B, NCED1, GGCT2;2 HSP22.0, WRKY53, HSP22.0, WRKY40, WRKY54) confirmed that there was a significant positive correlation between the two.