Diamond-like B-C-N compounds have the excellent potential properties like diamond or cubic boron nitride. In this paper, diamond-like B2(CN)3 compound has been studied by first principle calculations. After geometry optimization, hexagonal and monoclinic B2(CN)3 models were obtained. According to the band structure and density of state calculated, they are conducting. The relative stability was proved using elastic constants calculated by Born criterion. The monoclinic B2(CN)3 is one of hard material with theoretical Vickers hardness 38 GPa.