Tumor fever is a type of fever whose mechanism of occurrence is not clear. It generally refers to non-infectious fevers directly related to cancer that occur in cancer patients when infection is ruled out and antibiotic treatment is ineffective, and to fevers caused by treatment of the patient in the process of tumor development. The elevated body temperature of tumor fever is low, and a few show high fever. The use of antibiotic treatment is generally not useful for lowering the body temperature of tumor fever, and the use of non-steroidal antipyretic drugs such as indomethacin will have a temporary antipyretic effect. In most patients, tumor fever will return to normal with effective control of the tumor disease. Possible causes of tumor fever are currently under clinical consideration as follows two. 1. Tumor tissue secretes abnormal substances as endogenous thermogenic source leading to fever. 2. Necrosis occurs in the larger tumor itself, or a large number of tumor cell necrosis occurs after treatment, and the necrotic material causes the body to experience absorptive fever.