A finite element is formulated to study free vibration of annular plates constrained by any combination of classical boundary conditions at outer and inner edges and also by internal concentric ring-shape simple support. Although this problem has been studied by a number of authors, few accurate results were presented by using the finite element method (FEM). It is therefore intended in this paper that a simple and straightforward FEM formulation is introduced and comprehensive sets of accurate natural frequencies are listed in tables for all combinations of classical boundary conditions and a range of internal support location.