In this study, we tested the ability of sodium dehydroacetate (SD) to extend the shelf-life of ‘Kyoho’ grape.  Among the different concentrations of SD tested (0, 0.01, 0.1 and 1.0 mmol L^–1), 0.01 mmol L^–1 SD was the most effective in prolonging the shelf-life of ‘Kyoho’ grape.  Compared with the control, the weight loss rate, browning index and hydrogen peroxide (H₂O₂) and malonaldehyde contents were significantly lower in the 0.01 mmol L^–1 SD treatment, whereas the healthy berry rate, berry firmness, total soluble solids (TSS) content, ascorbic acid content and superoxide dismutase (SOD) activity were significantly higher.  In addition, an analysis of ‘Kyoho’ grape DNA using methylation sensitive amplification polymorphism (MSAP) markers showed that the average DNA methylation level was significantly higher in the 0.01 mmol L^–1 SD treatment than in the control.  Together, these results indicate that 0.01 mmol L^–1 SD could be used to extend the shelf-life of ‘Kyoho’ grape.  Moreover, a strong connection between reactive oxygen species (ROS) metabolism and DNA methylation change during storage was revealed.