Abstract: In order to determine the effect of heat water treatment on the postharvest disease and physiological changes of peach fruits, peach fruits were dipped in 50 ℃ hot water for 1 min and then stored at 25 ℃.During the storage, disease incidence of fruits were investigated and the activities of antioxidant metabolic system enzymes ( APX, CAT, POD and LOX) and phenylpropanes metabolic system enzymes ( PAL) were analyzed. Meanwhile, the contents of phenylproanoid metabolites ( total phenolics, flavonoids and lignin) were measured. The results showed that disease incidence of fruits inoculated with Monilinia fructicola were inhibited effectively in heat treated sample. Heat treatment could effectively induce the APX, POD and PAL activities and inhibit the LOX activity. Meanwhile, the level of total phenolics, flavonoids and lignin were enhanced in peach fruits.These findings suggested that postharvest heat treatment stimulate the process of antioxidant, phenylproanoid metabolism and started defense reaction of peach fruits.