Abstract: In order to reduce flesh color changes in Nanhui peach (Prunus persica L. Batsch), which seriously affect their commercial value, carboxymethyl chitosan preservative and slightly acidic electrolyzed water were used to preserve Nanhui peaches. Changes in flesh color, and the quality characters related to flesh color were assayed periodically during storage at 2oC. T2-MAP made by magnetic resonance imaging (MRI) was used to check the inner quality of peaches at the beginning and end of the storage time. The results showed that the L* values, H* values, C* values of the control samples were 85%-91%, 85%-93% and 114%-122% higher than the two treated samples at the end of storage time, respectively (p<0.05). Compared with the control group, both carboxymethyl chitosan preservative and slightly acidic electrolyzed water can suppress ethylene production, decrease cell membrane permeability and changes in T2 relaxation constant, delay the increase in PPO activity and the accumulation of total phenolic compounds, thus decrease the peach flesh discoloration. Compared with slightly acidic electrolyzed water treatment, carboxymethyl chitosan preservative treatment was more effective in maintaining the quality of Nanhui peaches.