An organic precursor was synthesized with C3N6H6 and H3BO3 as raw materials in aqueous solution. A novel amorphous BCN compound was obtained by thermolysis of the precursor at 1900°C in flowing N2 atmosphere. Single crystal X-ray diffraction analysis reveals that the precursor is a supramolecular compound with a formula C3N6H6(H3BO3)2. The pyrolysis product was characterized by XRD, XPS, FTIR, and SEM. XRD results reveal that the pyrolysis product has a turbostratic graphite structure. XPS analysis confirms the formation of nitrogen-rich BCN ternary compound with an approximate composition of B3CN3. Both the deconvoluted XPS spectra and FTIR spectrum indicate that B-N, B-C, and C-N chemical bonds have been established and there is no phase separation of graphite and h-BN occurred, which suggests an atomic-level hybrid of B, C, and N in the compound. SEM images show that the crystal shape of the B3CN3 compound is columnar, which is similar to the precursor.