The optical-phonon spectra of CdGeAs2 were investigated by low temperature polarized Raman scattering. According to vibrational modes of ZnS-type Materials and selection rules of Raman scattering, all Raman active vibrational modes in the Brillouin-zone (BZ) center of CdGeAs2 predicted from group theory arguments were identified and-artificially grouped in three energy bands, including 45-94, 158-215 and around 260 cm(-1). Based on the Lyddane-Sachs-Teller (LST) relation and measured refractive indices, the low-frequency dielectric constant epsilon(0) is estimated to be 15.04 and shows good agreement with the previous tests and predictions. (C) 2016 Elsevier Ltd. All rights reserved.