Characterization of solid-to-solid contact thermal resistance is important for ITER solid breeder blanket designs utilizing sintered blocks of Be and/or solid breeder1. In order to fully assess the thermal performance of such blankets, including their ability to accommodate power variation, the thermal resistances of the Be/clad and solid breeder/clad contacts need to be characterized. In this paper, factors affecting the gas and solid conductances in the contact zone are analyzed. They include: roughness, contact pressure, temperature and curvature of restrained Be block. The study is carried out based on the models of Yovanovich2 and Shlykov3 and available experimental data from the literature. Recommendations are provided for the ITER solid breeder blanket design applications and for corresponding R&D requirements.