Based on the electro-optical energy transfer process, the pseudo-spectral-luminous efficiency function(ΦQD) of quantum dots(QDs) is introduced, the equations of chromaticity coordinates, luminous efficiency, and the QDs' mass of the white-light-emitting devices with Cd Se, Cu In S2 or Cd S : Mn QDs are obtained, and the calculated results are in agreement with the experimental data. For a certain luminescent peak wavelength, when the full width at half maximum of the QD's photoluminescence becomes larger, t...