The improved composition for use in the production of composite carbon materials comprises a mesophase pitch containing at least 80% of an optical anisotropic phase and having a softening point of no higher than 250.degree. C., and sulfur present in an amount of 6-35 parts by weight per 100 parts by weight of said mesophase pitch. Said composition may be heated together with an aggregate and subsequently shaped to yield a composite carbon material. The improved process for producing a composite carbon material comprises impregnating an aggregate with said composition as it is melted, shaping the mixture in a temperature range of 150.degree.-350.degree. C, and then carbonizing the shaped part.