  Using the new physical interpretation of quasinormal modes proposed by
Maggiore, we calculate the area and entropy spectra for the 3-dimensioal and
5-dimensional large AdS black holes. The spectra are obtained by imposing the
Bohr-Sommerfeld quantization condition to the adiabatic invariant quantity.
With this semiclassical method, we find that the spacings of the area and
entropy spectra are equidistant and independent of the AdS radius of the black
hole for both the cases. However, the spacings of the spectra are not the same
for different dimension of space-time. The equidistant area spectra will be
broken when the black hole has other parameters (i.e., charge and angular
momentum) or in a non-Einstein's gravity theory.
