Objective:Cinnamaldehyde was encapsulated in the liposome.Methods:Cinnamaldehyde was selected as the research object and the cinnamaldehyde liposomes were prepared by ethanol injection method. The effects of phospholipid concentration, ratio of phospholipid to cholesterol, ratio of phospholipid to cinnamaldehyde and injection velocity on the encapsulation efficiency, particle size and polydispersity index (PDI) of cinnamaldehyde liposomes were investigated, and the process was optimized by response surface method with the encapsulation efficiency as the index.Results:The optimum preparation conditions of cinnamaldehyde liposomes were as follows: the phospholipid concentration was 2.69 mg/mL, the ratio of phospholipid to cinnamaldehyde was 6.73, and the ratio of phospholipid to cholesterol was 5.79. Under the control of these conditions, the encapsulation efficiency of cinnamaldehyde liposome was 82.37%, and the particle size and zeta potential were 113.89 nm, and-29.07 mV, respectively. After 4 weeks of storage at 4 ℃, it still has a high encapsulation efficiency and good stability.Conclusion:Cinnamaldehyde liposomes with small particle size, high encapsulation efficiency and stable properties could be prepared by ethanol injection method.