A unit cell model aimed at representing the microstructure of graphite foam is developed in this paper. The geometry of this model can be easily changed to accommodate different pore structures in graphite foams. With this model, the effective thermal conductivity and the interior surface area to volume ratio of graphite foam are obtained. Comparisons of the effective thermal conductivity between the current model and published results show good agreement. The investigation show that the increase of the porosity and the diameter of the openings decrease the effective thermal conductivity while the fluid thermal conductivity has negligible effect on the effective thermal conductivity of graphite foam. (C) 2011 Elsevier Ltd. All rights reserved.