[en] There is now discussion about clearance of materials and disposal of radioactive waste generated from uranium utilizing facilities which include uranium conversion and enrichment facilities, and fuel fabrication facility among the nuclear fuel cycle in Japan. These materials are supposed to be contaminated with natural nuclide, i.e. uranium. Uranium is widely distributed in the environment, e.g. soil, rock, river-water, groundwater and so on. Furthermore, uranium is also contained in some building materials and consumer goods. Literature survey was carried out to study distribution of uranium in the environment and measurement of uranium concentration in some materials. As a result, it is revealed that U-238 activities in soils in Japan range from order of several 1/100 Bq/g to several Bq/g. Addition to that, the range of building materials is overlapped by that of soils, while some consumer goods showed relatively high activities. Furthermore, dose contribution of uranium series nuclides to the environmental radiation dose was discussed. It was suggested that, sum of environmental radiation dose in Japan is about 1.5 mSv/y and dose contribution of uranium series nuclides is about 0.8 mSv/y. (author)