In order to study the effect of low-power microwave treatment on the postharvest quality of Kyoho grape, the grapes were treated with 32.5, 65.0, 97.5 and 130.0 W microwave respectively. The untreated grapes were used as the control, and all Kyoho grape stored at 0～2 ℃ for 40 days. The results showed that the low-power microwave treatment below 97.5 W had positive effect on the preservation of grape, which could prolong the ripening and senescence of Kyoho grape.The group with 32.5 W low-power microwave treatment had the best effect compared with the control in the end of storage period.which inhibited the rapid increase in the content of malondialdehyde, and the DPPH radical scavenging rate was higher than the control group about 33%. The shattering rate was decreased by 10% and the enzyme activity of PPO and POD was lower about 1/3 than the control.