[en] In National Institute of Radiological Sciences, a survey was made on radioactivities in the environment due to the substances released from nuclear installations and radioactive fall-out brought out by nuclear explosion tests since 1959. As the marked progress of non-military utilization of nuclear energy the national concern on environmental radioactivity has been increasing in Japan and thus it has become more and more important to make a survey research of radioactivities, which might affect the environment and human health. In these situations, the institute attempted to make the following six surveys in the fiscal year of 1998; 'a survey on radioactive levels in environment, foods and human bodies', 'survey on the radioactive level in the regions around nuclear installations', 'works in radioactive data center', 'fundamental survey on the evaluation of the results from radioactivity survey', 'workshop for technical experts of environmental radioactivity monitoring' and 'survey research on the measurement and countermeasures for emergency exposure'. (J.P.N.)