The effects of exogenous melatonin on postharvest ripening of mango (Mangifera indica L. cv. Keitt) were investigated after the fruit were dipped in 0 (as the control), 100, or 200 μM melatonin solution for 30 min, and then stored at room temperature (25 ± 1 °C). The results showed that melatonin treatments could delay the ripening process as indicated by inhibition to softening, respiration, color change and chlorophyll degradation in fruit during storage. Notably, 200 μM melatonin treatment delayed the degradation of phosphatidylglycerol (PG) and phosphatidylinositol (PI), and the accumulation of phosphatidylserine (PS) and phosphatidic acid (PA) in membrane phospholipids, inhibited the decrease in unsaturated fatty acids (IUFA) index and also decreased the contents of H 2 O 2 and malondialdehyde (MDA) in the exocarp of the fruit, which might collectively contribute to the integrity of the membrane associated with the delay in the ripening process of mango fruit during postharvest. • Melatonin treatment delayed the postharvest ripening process of mango. • Melatonin treatment altered the composition in membrane phospholipid of mango. • Melatonin treatment suppressed the decline in index of unsaturated fatty acid of mango. • Melatonin treatment reduced the chlorophyll degradation in the peel of mango. [ABSTRACT FROM AUTHOR]