OBJECTIVE To investigate the inhibition of 2-methoxyestradiol liposomes on S₁₈₀ ascites tumor in mice. METHODS 120 Kunming mice with ascites tumor were distributed into six groups at random：control group， 5-fluorouracil group， 2-methoxyestral solution， 2-methoxyestradiol liposomes 30.0， 22.5， 15.0 mg·kg^-1·d^-1 groups. All the treatments were given for 7 d and the interval was 24 h. The abdomen circumference of the mice were recorded in all groups every two days. Ascites volume inhibition and cell persistence of mice were evaluated as well as the cell cycle and apoptosis. The pathologica changes of liver were observed by optical microscope. RESULTS Mice in treated groups attained longer survival time， ascites volume inhibition and lower cell persistence. CONCLUSION Intraperitoneal administration of 2-methoxyestradiol liposome is effective for the treatment of S₁₈₀ ascites mice， and could inhibite metastasis of ascites cell in abdominal cavity. The curative effect of 2-ME liposome is dose-dependent.