The effect of chitosan ginger essential oil coating preservation treatment on active oxygen metabolism of fresh tremella was investigated. The concentration of 1.0% chitosan ginger essential oil was used to treat fresh tremella,and the effects of chitosan ginger essential oil on disease resistance and active oxygen metabolism of fresh tremella were determined. The results showed that chitosan ginger essential oil coating treatment significantly reduced the disease incidence and index of fresh tremella (P<0.05). In the early stage of storage,the contents of O₂^-·,the activities of PPO,CATand SODwere increased,and the POD activity was inhibited. The results showed that chitosan ginger oil coating treatment could induce reactive oxygen species (ROS) and accelerate ROS scavenging reaction intremella,also enhance disease resistance,delay the maturity and senescence of fresh tremella. The ultrastructure observation showed that the chitosane-ginger essential oil membrane forming liquid formed a dense network structure,adhered to the surface of tremella,filled the space of tremella mycelium cells,isolated the infection of external microorganisms,and prevented the loss of water and nutrients of fresh tremella.