Combining effect of hyperthermia and intratumoral injection of epinephrine and anti-cancer drugs was studied using Lewis lung carcinoma. Epinephrine injected intratumorously sensitized the effect of hyperthermia and the effect of PEP, DWA2114R, and MMC injected intratumorously. These anticancer drugs injected intratumorously also had synergistic effect with hyperthermia. The combining effect of them was the greatest and almost additive of the combined effect of anti-cancer drugs and hyperthermia and that of epinephrin'e and hyperthermia. The combining effect tended to be more prominent at lower temperature (40.5°C) than that at higher one (43.5°C), especially in DWA2114R. Number of lung metastases was not differect significantly among each treatment. These findings suggested that the combined treatment would be useful, especially in mild hyperthermia.