Abstract: The behavior of thermal conduction of dispersion fuel elements depends on the heat generation of the fissionable particles,the volume fraction and size and array mode of the particles,the geometrical configuration of the element and the thermal circumstance in the reactor core.Following the idea of micromechanics of particle reinforced composites,a representative volume element or a unit cell is chosen and the finite element analysis is applied to study the effective thermal conductivity coefficient of the fuel element.The effects of temperature,burnup and volume fraction of the fissionable particles on the coefficient are investigated in details.The results are compared with several analytical equations and indicate that the Maxwell’s model provides the best agreement with the FEM data.