Objective：To research the preparation methods，prescriptions and preparation properties of osthole loaded liposomes，and the lyophilized liposomes was prepared to improve the stability of the preparation. Methods：Encapsulation efficiency was taken as index to screen the preparation of liposomes；the formulation was optimized by single factor prescription analysis and orthogonal test. The encapsulation efficiency，particle size and potential of the osthole
liposomes were measured，and the morphology under transmission electron microscope was observed；mannitol was selected as a freeze-drying agent，we explored the effect of its addition on the encapsulation efficiency of lyophilized liposomes. Results：The liposomes were prepared by ethanol injection method. The optimal formulations were EPC 4 mg·mL-1，CHOL 5 mg，Ost 2 mg，and at 50℃ reactive temperature. The encapsulation efficiency of liposome was （83.09±0.56） %，the particle size was（ 101.9±2.7） nm，and the potential was（ -15.3±2.3） mV. When the amount of mannitol was 8%，the lyophilized liposomes had better morphology and less leakage.Conclusion：Liposome which has high entrapment efficiency and well-distributed particle size was prepared by ethanol injection. After preparation of lyophilized liposomes，the stability of liposomes was improved.