Objective: To prepare vinblastine hydrophilic group-modified cationic liposomes and investigate their physicochemical properties. Method: Vinblastine hydrophilic group-modified cationic liposomes were prepared by pH gradient method.Morphology of liposomes was detected by transmission electron microscopy

particle size distribution and Zeta potential was investigated by laser scattering

degree of oxidation was measured by oxidation index method

sephadex G-50 was applied to separate free drug and liposomes in order to determine entrapment efficiency and leakage efficiency of liposomes. Result: Particle size of liposomes was (102.4±3.8)nm with a narrow polydispersity index of 0.18±0.01

bilayer of these liposomes was observed obviously with a Zeta potential of (27.4±0.58)mV.Oxidation index of liposomes was less than 0.2

entrapment efficiency of vinorelbine was 86.42%.Leakage rate was less than 8.0% prevented in refrigerator (<4 ℃) after nine months

while this index was 34.8% at room temperature. Conclusion: Vinblastine hydrophilic group-modified cationic liposomes have uniform particle size and fine-looking with high entrapment efficiency.Leakage rate of liposomes is close to storage temperature.