Abstract: 【Objective】 To investigate the inhibitory effect of pre-harvest spraying of CaCl₂ (Calcium chloride) on post-harvest senescence of prune fruits. 【Methods】 French prunes from Gashi County, Kashgar Prefecture, Xinjiang, as the test material for the study. The relationship between fruit senescence and active metabolism was analyzed by measuring the activities of enzymes related to active oxygen metabolism using 2% CaCl₂ sprayed at the expansion, colour change and harvesting stages of the fruit. 【Results】 The results showed that the pre-harvest CaCl₂ treatment delayed the decrease of post-harvest fruit weight loss, total phenols and flavonoids, and inhibited the increase of malondialdehyde and accelerated the scavenging of superoxide anion and hydrogen peroxide in the post-harvest fruits of prunes. Pre-harvest CaCl₂ treatment significantly increased the activity of Peroxidase (POD), Superoxide Dismutase (SOD), catalase (CAT), Ascorbate Peroxidase (APX) and Glutathione Reductase (GR), thereby delaying the decline in post-harvest fruit weight loss. After 21 days storage,the weight loss rate of fruits treated with CaCl₂ increased by 67.05%.The acitivies of POD、SOD、CAT、APX、GR increased by 30.21%、15.87%、57.46% and 50.49% respectively. 【Conclusion】 Therefore, CaCl₂ pre-harvest treatment reduces the accumulation of reactive oxygen species, mitigates oxidative damage in prune fruit, maintains the integrity of cell membranes thus delaying the ageing of prune fruit.