The work aims to explore the preservation performance of γ-aminobutyric acid (GABA)-chitosan coating on pepino fruits. The pepino fruits were stored at 12 ℃ for 28 d. The effects of 10 mmol/L GABA-chitosan coating treatment on the nutritional quality and physiological and biochemical parameters of pepino fruits during storage were investigated. Compared with the control group, GABA-chitosan coating treatment significantly improved the sensory quality of pepino fruits, inhibited their respiration, reduced weight loss, PPO and POD enzyme activities, maintained soluble solids and titratable acid contents, and slowed down MDA accumulation, while effectively maintaining high Vc and total flavonoid contents, thus delaying fruit softening and quality deterioration. Two principal components were extracted by principal component analysis (PCA), with a cumulative variance contribution of 86.86%, which could better explain the quality changes of pepino fruits during storage. In addition, PCA analysis revealed that the 28 d treatment group was closer to the 14-21 d control group, further confirming that the GABA-chitosan treatment contributed to the stabilization of the storage quality of pepino fruits. In conclusion, GABA-chitosan coating treatment can delay the postharvest softening, browning and senescence of pepino fruits, thus improving the storage life of the fruits.