The paper aims to study the effect of modified atmosphere treatment on the quality of postharvest actinidia arguta fruit. The actinidia arguta was placed in a sealed air conditioning preservation experiment box and an opened air conditioning preservation experiment box (serving as control), and then stored at 4 ℃ for 64 d. The respiratory metabolism and resistance indexes such as the concentration of CO2 and O2 in the box, the contents of total soluble solids (TSS), malondialdehyde (MDA) as well as total phenolic, and antioxidant enzyme activity were analyzed every 16 d. The results showed that modified atmosphere treatment could maintain proper CO2 and O2 concentration to maintain higher TSS and total phenolic contents, inhibit MDA content and polyphenol oxidase (PPO) activity as well as enhance the activities of peroxidase (POD), phenylalanine ammonia lyase (PAL) and catalase (CAT). Therefore, during the storage of 48~64 d, the most suitable gas environment for modified atmosphere treatment of actinidia arguta is about 3% CO2 volume fraction and 16% O2 volume fraction. The mechanism for maintaining the quality of actinidia arguta is based on inducing phenylpropanoid and antioxidant metabolism.