Major and hypothetical accidents for siting evaluation of the High Temperature Engineering Test Reactor (HTTR) are evaluated. The purpose of the evaluation is to show the property of site location, i.e. a distance between the facilities and the public is kept enough so as to ensure the safety of the public even under the major and hypothetical accidents. The HTTR is a high temperature gas-cooled reactor adopting of coated fuel particles as fuel and graphite as moderator and core internal structures. Then the core temperature changes slowly and the instantaneous failure of coated fuel particles does not occur in accident conditions. Therefore, selection and analysis of siting evaluation events have been performed by methods different from LWRs`. A double-ended rupture of coaxial double pipe of the primary cooling system is selected as the major and hypothetical accident for siting evaluation of the HTTR. In order to evaluate radiation exposure during the accidents, time-dependent release of fission products which are contained in the core is assumed considering the above mentioned characteristics of the HTTR. This paper describes the selection of the events, analytical method are results of radiation exposure in the major and hypothetical accidents of the HTTR. (author).