Abstract: Sweet cherries are susceptible to quality deterioration during postharvest storage and transportation, including flesh softening and spoilage, which greatly reduce their commercial value. In order to preserve postharvest quality and extend the shelf life of the fruit, this study utilized ‘Samituo’ sweet cherries as the experimental material to investigate the effects of pre-harvest spraying with alginate oligosaccharides at concentrations of 50, 100, and 200 mg/L on fruit quality-related parameters and the activities of cell wall degrading enzymes during low-temperature storage. The results indicated that the pre-harvest application of alginate oligosaccharides at various concentrations effectively delayed the decline in soluble solids content, titratable acidity, and fruit firmness, while also reducing the rate of fruit weight loss, as compared to the control group. Treatment with alginate oligosaccharides delayed the decline of L^*, a^*, and b^* values and color saturation, while also inhibiting the activities of pectate lyase, pectin methylesterase, polygalacturonase, cellulase, β-galactosidase, β-glucosidase, pectin methylesterase and polygalacturonic acid transeliminase. Among the treatments, 200 mg/L alginate oligosaccharides exhibited the most pronounced effect. The correlation analysis reveals that titratable acidity was significantly and positively correlated with the activities of β-galactosidase and pectin methylesterase, while was distinctly negatively correlated with the activities of polygalacturonase and cellulase. In contrast, soluble solids content exhibited a significant negative correlation with polygalacturonase, cellulase, polygalacturonic acid transeliminase, pectate lyase, and β-galactosidase activities. Furthermore, fruit hardness showed a significant negative correlation with the activities of polygalacturonase, cellulase, pectate lyase, and β-glucosidase. Weight loss was significantly positively correlated with polygalacturonase and cellulase activities, whereas it was significantly negatively correlated with the activities of polygalacturonic acid transeliminase, pectin methylesterase, pectate lyase, β-glucosidase, β-galactosidase, and pectin methylesterase. These findings suggest that pre-harvest application of alginate oligosaccharides can delay fruit softening and maintain storage quality by suppressing the activity of enzymes related to fruit cell wall degradation.