The wok aims to study the influence of the treatment by chitosan oligosaccharide coating incorporated with plant essential oil on the quality of fresh-cut apples. The fresh-cut apples were respectively treated for 2 min by the distilled water, chitosan oligosaccharide, chitosan oligosaccharide +0.25% thyme oil, chitosan oligosaccharide + 0.06% cinnamon oil, and chitosan oligosaccharide + 0.25% thyme oil + 0.06% cinnamon oil. Then, the samples were air-dried on the sterile filter paper, sealed by PVC fresh-keeping film after placed on the pallet and stored at 4 ℃. The samples were taken out respectively after 0, 3, 6, 9, 12, 15 and 18 days, and all their physiological and biochemical indexes (i.e. luminance (L*), color (C*), hardness, mass loss rate, content of ascorbic acid, activity of polyphenol oxidase, peroxidase activity and lipoxygenase activity) were measured. The coating treatment of chitosan oligosaccharide + 0.25% thyme oil + 0.06% cinnamon oil could significantly maintain the color, harness and content of ascorbic acid of the fresh-cut apples. The PPO and POD activities were lower than other processing groups. The chitosan oligosaccharide coating could remarkably delay the mass loss of the fresh-cut apples, reduce the lipoxygenase activity in the samples and prolong their aging speed. The chitosan oligosaccharide coating has a good preservation effect for fresh-cut apples, and can better maintain their quality after incorporated with the composite essential oil during the storage.