The equilibrium geometries, vibrational frequencies, atomization energies, adiabatic electron separations, adiabatic detachment energies (ADE), and adiabatic ionization potentials of the low-lying electronic states for the NaAs4 clusters and its ions were investigated employing the DFT method, and then compared with the photoelectron spectra.According to the computed results, reasonable assignments for the photoelectron spectra of NaAs4- were suggested.