Abstract: Taking ‘Zhenyu’ zucchini as test material, the effects of melatonin treatment on chilling injury, fruit quality, and antioxidant enzyme activity of zucchini during low-temperature（4±0.5）℃ storage were investigated, which expect to provide a reference for the storage of zucchini.The results showed that melatonin treatment significantly reduced the chilling injury index, chilling injury incidence, and weight loss rate, inhibited decreases in chlorophyll and increases in a^* value and b^* value, while maintained higher firmness and vitamin C levels of zucchini fruits.In addition, melatonin treatment increased the activities of superoxide dismutase, catalase, glutathione reductase, and ascorbate peroxidase, inhibited increases in relative membrane permeability and malondialdehyde content of zucchini fruits.In conclusion, the melatonin treatment might alleviate chilling injury in zucchini by increasing antioxidant enzyme activity and maintaining cytomembrane permeability.