The equilibrium geometries, excitation energies, force constants and vibrational frequencies for the low-lying electronic states X 3-SIGMA-, a 1-DELTA, A 3-PI and 1 1-PI of the N3+ ion have been calculated at the MRSDCI level with a double zeta plus polarization basis set. Our calculated excitation energies and vibrational frequencies for these electronic states are in good agreement with available experimental data obtained via UV photoelectron spectroscopy of the N3 molecule. The electronic transition dipole moment, the oscillator strength for the A 3-PI --> X 3-SIGMA- transition, the radiative lifetime for the A 3-PI state and the spin properties for the X 3-SIGMA- state are calculated based on the MRSDCI wavefunctions.