In this paper, the finite-difference time-domain (FDTD) method is applied to calculate the resonant frequency of dielectric resonators (DR's) with curved surface, The contour-path integral FDTD (CFDTD) is modified to deal with the curved surface of the dielectric body while the traditional rectangular cells are maintained, Results are compared with theoretical values and staircase approximation, and show that the present method is more accurate than the staircase approximation.