This article reviews recent progress in the syntheses of B-C-N ternary materials. A number of B-C-N graphites of various stoichiometry have been synthesized via chemical vapor deposition and pyrolysis of precursors. One of the typical compositions, BC2N, has been relatively well-characterized, revealing that it is a genuine B-C-N compound with a semiconductive nature with a bandgap around 2 eV. Static and dynamic compressions on the B-C-N graphites have been conducted to explore the phase relationship and stability of B-C-N high-pressure phases. The results from these studies can systematically be understood by the fact that segregation into diamond and cBN is thermodynamically favored rather than formation of a B-C-N diamond-like compound.