Abstract: In order to investigate the effect of γ-aminobutyric acid (GABA) treatment on active oxygen metabolism and membrane lipid peroxidation of Agaricus bisporus, A. bisporus were dipped for 5 min in 5 mmol/L GABA, then stored at 4℃ for 12 d. Changes of the browning, membrane permeability, lipid peroxidation, reactive oxygen species, and antioxidant enzymes activity in the mushroom tissue were measured. The results showed that the GABA treatment could significantly increase the activities of SOD and CAT, and reduce the relative leakage rate, the production rate of superoxide anion and the accumulation of the contents of MDA and H₂O₂.And then, the cell membrane permeability and lipid peroxidation were delayed. Furthermore, the browning of A. bisporus was inhibited with higher L^* value and lower browning index. Therefore, GABA could be used as a color preservative for A. bisporus.