Density Functional Theory (DFT) was implemented to investigate the electronic structure of single layer graphene doped by boron (B) and nitrogen (N) in ortho-, meta-and para-positions at a doping ratio of 12.5%.The band structure, density of states, electron density and electron density difference were calculated.The results illustrate that a splitting appears between valance and conduct bands, which belongs to direct band gap.Furthermore, the band gap of B, N-co-doped graphene in meta-position is 1.296 eV, which is the smallest in these three different doped configurations.During the electronic redistribution, the charge transfer and hybridization among B, C and N atoms mainly occurs on the 2 p orbitals, furthermore, the hybrid orbital distribution of B-C atom is closer to the Fermi energy level and the energy distribution of C-N atom hybrid orbital is in the lower energy range.