We have systematically studied the structures, electronic properties, and lattice dynamics of B–P compounds at high pressures. BP and B6P are found to be thermodynamically stable below 100 GPa, and other stoichiometries are decompos-able under pressure. The predicted structures of F-43m BP and R-3m B6P are in good agreement with the experimental results by comparing the powder diffraction file (PDF) standard cards with our simulated x-ray diffractions. The bonding properties of BP and B6P have also been analyzed by electronic localization functions, charge density difference, and Bader charge analysis. Our results show that BP and B6P decompose into B and P under high pressure, which is proven to be dominated by the volumes of them. Furthermore, the infrared and Raman spectra of F-43m and R-3m are investigated at selected pressures and will provide useful information for future experimental studies about B–P compounds.