The purpose of this studv was to investigate the vibration modes of tooth and explain the vibration characteristics of tooth.By using the finite element method (FEM) software,the Eigen vibration of 3-D finite element model of maxillary central incisor tooth was analyzed.Crown vibration was dominantly present in the natural modes.In general,tooth vibration was mostly dominated by the first 4 natural modes and the natural frequencies of the tooth studied were 879.65,1286.76,1827.21 and 2087.59 Hz,respectively.