In patients with unresectable HCC, transcatheter arterial chemoembolization (TACE) is a widely used treatment. Recently, as an alternative treatment modality for HCC, transcatheter arterial embolization with radioisotopes has been investigated. In this study, we compared the therapeutic efficacy of an intra-hepatic arterial injection of Re-188-MN-16ET-lipiodol and the TACE method in rats with liver tumors. Twelve male rats bearing hepatic tumors were divided into three groups to evaluate the efficacy of treatment (four in each group). Group 1 received an intra-hepatic arterial injection of 0.2mCi of Re-188-MN-16ET-lipiodol; group 2 received epirubicin (0.5mg/kg) and 0.1ml of lipiodol emulsion; group 3 received 0.1ml of normal saline and served as the control group. Tumor size was measured by liver sonography before injection, at two weeks, four weeks and eight weeks after injection. Survival time was calculated from the day of treatment to 56days after treatment by the life-table method. The response to treatment and the survival time in each group were evaluated and compared. All rats treated with Re-188 MN-16ET-lipiodol showed good response to the therapy. Their tumor size decreased and all rats survived over eight weeks. All rats treated with epirubicin plus lipiodol survived over 8weeks; however, two rats (50%) showed increased tumor size in the 8th week. As for the control group (rats treated with normal saline), all rats survived less than 37days with continuous tumor growth. Results showed that Re-188-MN-16ET-lipiodol can be a potential therapeutic pharmaceutical for the treatment of liver tumors.