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The effects of malondialdehyde on bovine mitochondrial microstructure and metmyoglobin reduction ability were evaluated by measuring membrane permeability, malondialdehyde binding capacity, microstructure, electron transport chain-mediated metmyoglobin reduction and NADH-dependent metmyoglobin reductase activity. Compared with control groups, mitochondria incubated with malondialdehyde were increased significantly ( P <0.05) from membrane permeability and fluorescence intensity. As a result, mitochondria were swollen, mitochondrial cristae were partially disappeared and some of which were slightly vacuolated. Mitochondria incubated with malondialdehyde at pH value of 7.4 (storage condition) had a greater membrane permeability and higher fluorescence intensity ( P <0.05) than those of at pH value of 5.6 (physiological condition), which indicated that malondialdehyde reacted with mitochondrial membrane more easily under physiological condition, resulting in more serious injury to membrane. Succinate promoted the electron transport chain-mediated metmyoglobin reduction, the relative metmyoglobin contents were decreased by 21.70% and 12.87% ( P <0.05) at pH values of 5.6 and 7.4 compared with control groups (without succinate), respectively. Nevertheless, mitochondrial electron transport chain-mediated metmyoglobin reduction was inhibited when incubated with malondialdehyde, the reduction amounts of metmyoglobin were decreased by 15.68% and 3.83% ( P <0.05) at pH values of 5.6 and 7.4 compared with control groups (without malondialdehyde), respectively. In addition, NADH-dependent metmyoglobin reductase activity was also inhibited by malondialdehyde, which was decreased by 48.97% and 47.80% ( P <0.05) respectively when incubated with malondialdehyde at pH values of 5.6 and 7.4. In conclusion, malondialdehyde could injure the microstructure of mitochondria and inhibit the mitochondria mediated metmyoglobin reduction, which was disadvantageous to color stability of fresh beef. Therefore, it is meaningful to reduce lipid oxidation and maintain mitochondrial respiratory function for protecting color stability during storage.