[en] By using time-dependent density functional theory, the vertical excitation energies of the boron monoiodide molecule are calculated. The Vosko-Wilk-Nusair functional with Stoll correction is used as the local density approximation, while the RPBE functional is used as the general gradient approximation for the calculations of vertical excitation energies. The potential energy curves of the ground state, the 12 valence states and the eight Rydberg excited states are plotted. The spectroscopic constants, including the equilibrium internuclear distance, r_e, the harmonic vibrational wavenumber, ω_e, and the relative electronic energy referred to the ground state, T_e, of bound states, are obtained theoretically for the first time. The transition properties of the ¹ Π-X ¹Σ⁺ transition, including the transition dipole moments, the radiative lifetimes and the Franck-Condon factors, are predicted