To evaluate the influence of surface SiC coating and intermediate SiC/C layers on the mechanical strength of graphite matrix of the developed compositionally gradient graphite materials, which are composed of a surface SiC coating layer, an intermediate SiC/C layer and a graphite matrix, bending and compressive tests were carried out for SiC/C compositionally gradient graphite materials, SiC coated graphite materials, graphite materials with the intermediate SiC/C and virgin graphite materials at room temperature. The results of the tests were discussed in comparison with the specific surface areas which is a measure for the surface condition of samples. For the graphite with the intermediate SiC/C layer, the strength was independent of the Si content in the intermediate SiC/C layer and almost the same as that for the graphite substrate, although the specific surface area increased with an increase in the Si content in the intermediate SiC/C layer. The strength of the surface SiC coated specimens, i.e., SiC/C compositionally gradient graphite materials and SiC coated graphite materials, was about twice as that of the respective substrate, i.e., the graphite with the intermediate SiC/C layer and the virgin graphite. (author).