At elevated temperatures of 1000-1500 K, carbon (C) atoms that segregated to a surface and mixed with the boron (B) honeycomb lattice resulted in the formation of three different BC(x) layers as the topmost layers of NbB(2)(0001). Two of the layers were commensurate lattices: √7 × √7 and √3 × √3 structures; the third was incommensurate. The characteristic features of the √3 × √3 lattice with a honeycomb structure are discussed on the basis of the experimental data.