  The spectroscopy of a weakly isolated horizon (WIH) has been investigated. We
obtain an equally spaced entropy spectrum with its quantum equal to the one
given by Bekenstein [5]. We demonstrate that the quantization of entropy and
area is a generic property of horizon, and the results exit in a wide class of
spacetimes admitting weakly isolated horizons. Our results also indicate that
the entropy quantum of the black hole horizon is closely related to Hawking
temperature.
