Abstract: The total body irradiation (TBI) is an important treatment part for the patients with leukemia or cancer.But the realization of the TBI has to have regard to the present treatment machines and the possibilities of their arrangement in the radio-oncology department, e.g the X-ray energy, the maximal field size and the size of the treatment room.The irradiation techniques used in the different radiotherapy center are different.And the treatment planning of total body irradiation shows partially other problem than the conventional treatments.The treatment parameters used in TBI are more than the conventional treatments.So it is very important to compare the all kinds of treatment techniques and the clinical results in different radiotherapy centers.This article will describe the dosimetry methods of the TBI in 4 parts below.