In solid breeder blanket design of fusion power plants, the ceramic breeder pebble bed plays a very important role. Its mechanical and thermal properties are necessary to design the blanket. In this study, thermomechancal properties of the bed such as effective thermal conductivity and stress-strain relation are investigated by means of numerical simulation. A discrete element manner is adopted in the simulation in order to clarify the influence of the individual particle properties upon the bulk behavior. As a result, the thermo-mechanical properties of pebble bed were well re-created in a computational space by means of the numerical model used in this study.