Abstract: Field-Cycling-Technique has boon successfully used for nuclear quadrupole double-resonance to investigate imperfections in crystals, to raise the sensitivity of the measurements and to measure the imperfections in Li₃N. Quadrupole splittings of the imperfections and the double-resonance process are analyzed in this paper. At the end of this paper, a brief discussions is given to the measured absorption lines of Li₃N.