Conjugates of monoclonal antibody COC166-9 and adriamycin entrapped in liposome (MLA) were prepared in our laboratory. In vitro growth inhibition of SKOV3 ovarian carcinoma cell line was carried out by MLA and controls. Target therapies by MLA, adriamycin, normal mouse IgG instead of MAb, and control were given for 24 nude mice models with subcutaneous human ovarian carcinoma xenografts and 16 ascitic ovarian carcinoma respectively. MLA group showed the best therapeutic effect than all the other groups which gave a helpful clue to clinical use.