Abstract
An information on the learning of radioactivity in secondary education was obtained through two questionaires for 1, 871 pupils and students. More than 50% of the pupils and 80% of the students had the elementary knowledge of the atomic structure, the radioactive disintegration and the radiations such as α-, β- and γ-rays. Some different patterns were found in the responses of the pupils corresponding to whether the questions were in the subject areas in school or not. The majority of the studens had a poor understanding for the concept of -dN/dt=λN. On the basis of the information, it was discussed to modify the instructional materials about radioactivity used in the secondary education.
