Abstract: Objective: This study investigates the effects of dwarfing treatment on the appearance and postharvest quality of banana fruits. Methods: The experimental material used in this study was 'Guijiao No.9'. A dwarfing agent, primarily composed of uniconazole and potassium dihydrogen phosphate, was dissolved in water and applied to the roots. The banana seedlings undergo their first treatment with the dwarfing agent when they reach the 18th leaf, followed by a second treatment when they reach the 23rd leaf. The fruits were harvested once they reach the desired level of commercial maturity. Fruit appearance (peduncle length, fruit finger circumference) and postharvest quality, including peel color (value L^*, a^*, b^*, C^*, h^*), fruit hardness, respiration rate, ethylene release, soluble sugar content (fructose, sucrose, glucose), and organic acid content (oxalic acid, quinine acid, malic acid, succinic acid, V_C, citric acid, fumaric acid) in the flesh were taken as reference indicators to study the effects of dwarfing treatment on the storage quality of banana fruits. Results: The peduncle length and finger circumference between the dwarfed group and the control group showed extremely significant differences (P<0.01) and significant differences (P<0.05), respectively. Under the storage condition of 22 ℃, there was no significant difference in peel color chromatism and firmness change between the dwarfed group and the control group. After the climacteric stage, the CO₂ and ethylene production of the dwarfed group were higher than those of the control group, but with no significant difference. The malic acid content in the fruits of the dwarfed group was lower than that of the control group during the entire ripening period and reached a significant level at maturity stage 3 (P<0.05). At maturity stages 4 and 5, the succinic acid content in the dwarfed group was significantly lower than that of the control group, with extremely significant differences (P<0.01) and significant differences (P<0.05) were observed, respectively. The quinine acid content in the dwarfed group was significantly (P<0.05) lower than that of the control group at maturity stage 5. There was no significant difference in the content and trend of glucose, fructose, and sucrose between the two groups. Finally, at maturity stage 7, there was also no significant difference in the sugar-acid ratio between the two groups. Conclusion: The dwarfing treatment reduced the peduncle length and fruit finger circumference of Banana 'Guijiao No.9' and altered the metabolism of some organic acids, but did not significantly change the storage life and eating quality.