Nd(Mg1/2Sn1/2)O-3 (NMS) ceramic was synthesized using a conventional solid-state reaction method. Crystal structure and morphology were investigated through X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Lattice vibrational modes were obtained through Raman scattering and Fourier transform far-infrared reflection spectroscopy. The main phase is NMS with monoclinic P2(1)/n(1) symmetry proved by XRD. SEM shows sample is dense and well-crystallized ceramic. The Raman spectrum with active modes were fitted with Lorentzian function, then these modes were assigned and illustrated, respectively. For example, the highest wavenumber mode above 650 cm(-1) is attributed to A(1g)-like mode that corresponds to the symmetric breathing of oxygen octahedra. The far infrared spectrum with seven infrared active modes was fitted by using four-parameter semiquantum models to calculate intrinsic properties, which agree well with the data calculated from Clausius-Mosotti equation, as well as the relationship between the damping coefficient and the intrinsic loss. F-2u((2)) yielded the greatest contribution to dielectric constant and loss, which is primarily represented as the inverted translational vibration of Nd MgO6 octahedron. Aig(Nd) Raman mode in A-site has an enormous effect on the dielectric loss. The imaginary and real parts of the dielectric constant were obtained with the Kramers-Kronig analysis. (C) 2017 Published by Elsevier B.V.