Abstract: From December 1986 to May 1988, 25 cases of patient with late primary carcinoma of liver were treated with radio-frequency intertissue hyperthermia in our hospital. The survival rates of one year for single hyperthermia group aod hyperthermia plus radiation group were both higher than that for single surgery group. The clinical pathology of the heated liver was detailly discribed. The early reaction of the heated carcinomous tissue appeared mainly acute inflammation. And the late reaction be coagulation necrosis which was wholly surrounded by a lot of fibrotic tissues. Organition phenomenon of the intravascular thrombi and many newborn hepatic cells with varied volnm but bigger nucleus or double nuclei might be seen near the necrostic tissues. These demonstrated the benefit of heat treatment for the primary hepatic carcinoma. The clinical examination items for response evaluation after hyperthermia were also discussed.