To study the effects of different modified atmosphere packaging on the postharvest quality and chlorophyll degradation in Chinese kale during storage, Chinese kale samples were packed with commercial micro-porous low-density polyethylene (LDPE) bags and two kind of modified LDPE bags. The gas content and quality changes of Chinese kale in the packaged bags were detected periodically. The results showed that during the storage at 15℃,the content of O₂ decreased and CO₂ increased significantly in the modified atmosphere packed bags, while no obvious changes for volume fraction of either O₂ or CO₂ in control group. Both of the modified atmosphere packaging groups exhibited similar effects on retarding the yellowing process and weight loss rate, and maintaining higher content of chlorophyll, vitamin C and soluble proteins ratio in leaves during storage. The commodity rate of two modified atmosphere packaging groups maintained at 100% on the third day of storage, and leaf chlorophyll mass ratio decreased slightly with 14.67% and 4.74%, respectively. Comparably, the commodity rate of the control group declined rapidly to 51.25%, and the leaf chlorophyll mass ratio decreased by 26.47%. The content of chlorophyll during leaf yellowing of Chinese kale regulated by the gene expression of CLH1, PPH, PAO, RCCR and NYC, and CLH1 took effect for the chlorophyll-degrading enzyme mainly at the early period of leaf yellowing. The modified atmosphere packaging treatments could slow down the physiological changes, inhibit the expression of gene involved in chlorophyll degrading enzyme, thus, delay the leaf yellowing in Chinese kale during storage. The result could provide a theoretical basis for controlling the postharvest quality deterioration and storage of Chinese kale.