Abstract: Experiments were conducted to study the effects of nitric oxide (NO) on active oxygen metabolism of postharvested‘Baili’tomato. The results showed that the application of NO delayed the respiration and ethylene peaks, inhibited the O·2 and H₂O₂ accumulation, maintained a higher level of the activities of SOD, CAT, POD, APX and the content of GSH and AsA at the late stage of fruit storage during active oxygen metabolism, slowed down the increase of MDA content and the relative membrane permeability, reduced the preoxide action of membrane lip ids, and postphoned the fruit senescence.

Key words: Tomato, Nitric oxide, Metabolism of active oxygen, Senescence