Compared with carbon nanocones, Boron Nitride Nanocones (BNNCs) are characterized by different physical, chemical, and electronic properties. Since BNNCs are in three types of covalent bonds (B-N), B-B, and (N-N), carbon nanocones contain only C-C bonds. Given that the structural properties of nano cones depend on the disclination angle of the cone, the current study aims to discuss the electronic and structural properties of boron nitride nanocones in different sizes (height and disclination angle) using Density Functional Theory (DFT) calculations. To this end, the relevant calculations were done for boron nitride nanocones with the cone heights of 1 to 5 angstroms at the disclination angle of 60°, 3 to 7 angstroms at the disclination angle of 120°, and 4 to 8 angstroms at the disclination angles of 180 and 240°. In this work, the density of states, quantum parameters, analysis of bond order, bond length, polarizability, anisotropic polarization, dipole moment, atomic charges, and frequencies were calculated using the DFT. According to the results, the best structure was identified based on the height and disclination angles to be further used in the next calculations. It is hoped that the results of this project can be useful in expanding the experimental works and effective in the design of nanocones as well in order to absorb gases, drugs, etc.