Radiation safety training courses in School of Engineering, The University of Tokyo, were introduced. The number of radiation workers and the usage of radiation and radioisotopes have been surveyed for past 14 years. The number of radiation workers in School of Engineering has increased due to the treatment of X-ray analysis of materials, recently. It is important for workers to understand the present situation of School of Engineering before the treatment of radiation and radioisotopes. What the supervisor should tell to radiation workers were presented herewith. The basic questionnaires after the lecture are effective for radiation safety trainings.