Objective Agaricus bisporus was packaged using modified atmosphere with O2 , and the effects of different O2 concentration on the quality of Agaricus bisporus were studied. Methods The sensory properties ,respiration rate, hardness, weight loss rate, soluble solid content, whiteness and polyphenol oxidase (PPO) activity were measured during the storage period. Results Under storage conditions of 5 ℃ and RH 90% , high O2 could better maintain the hardness value ,whiteness value and sensory properties of Agaricus bisporus; treatment with 80% of O2 could inhibit the respiration rate and maintain the PPO activity; packaging with modified atmosphere with O2 had no significant effect on either the weight loss rate of the Agaricus bisporus or the soluble solid content. Conclusion 80% of O2 showed better preservation effect on Agaricus bisporus.