Abstract: To investigate the metabolic mechanism of 'Summer Black' grape fruit development after trunk girdling, physiological parameters and gas chromatography-mass spectrometry (GC−MS) were used to conduct metabolic analysis. It was found that the contents of TSS and SSC in fruits after trunk girdling were significantly increased, while the contents of TA were significantly decreased. Differential metabolites were significantly enriched in the pathways of galactose metabolism, starch and sucrose metabolism, ABC transporter, glyoxylic acid, and dicarboxylic acid metabolism. Sucrose and tartaric acid were the key metabolites involved in the above pathways, and their contents increased and decreased, respectively, thereby collectively promoting fruit ripening and improving fruit quality.