Renormalization of black hole entropy

We review the renormalization of one-loop effective action for gravity coup led to a scalar field and that of the Bekenstein-Hawking entropy of a black hole plus the statistical entropy of the scalar field. It is found that th e total entropy of the black hole's geometric entropy and the statistical e ntropy yields the renormalized Bekenstein-Hawking area-law of black hole en tropy only for even dimensional Reissner-Nordstrom (Schwarzschild) black ho les. We discuss the problem of the microscopic origin of black hole entropy in connection with the renormalization of black hole entropy.