The experimental results of polarized Raman scattering in KBr: Pb2+ single crystal after a long X-irradiation at 77K are reported in this paper. Based on the recently developed Behavior Type analysis method, it is confirmed that the peak at 186 cm-1 in Raman spectrum of KBr: Pb2+ corresponds to the vibration mode A′ of HD center with the symmetry of point group C1k(010).