[en] The environmental dose assessment can be divided into two major categories that are the assessments for the normal operation of nuclear facilities and for the emergency one. There, however, is no difference basically between the assessment procedures. The procedure includes the quantification of the source, the calculational method of atmospheric and ecological transports or the measurement method of radioactivity in the environmental samples, the estimation of the intake of radionuclides and the dosimetry. From the experience of Chernobyl accident, the precipitation scavenging has been recognized as the important deposition process of radionuclides from the atmosphere to the ground and plant surfaces. We measured about 10 times higher deposition on rainy days than it on clear days in May, 1986. The age-dependent dose assessment method is needed for the practical assessment of the dose of general public. The age-dependent parameters may include the organ mass, the biological half-life, the absorption and translocation factors and the energy absorption fraction. In this article, the method of environmental dose assessment is briefly described with the emphasis on the precipitation scavenging and the age-dependent dose assessment. (author)