It is shown that the hidden conformal symmetry, namely SO(2, 2) similar to SL(2, R)(L) x SL(2, R)(R) symmetry, of the nonextremal dyonic Reissner-Nordstrom black hole can be probed by a charged massless scalar field at low frequencies. The existence of such hidden conformal symmetry suggests that the field theory holographically dual to the four-dimensional Reissner-Nordstrom black hole indeed should be a two-dimensional conformal field theory (CFT). Although the associated AdS(3) structure does not explicitly appear in the near horizon geometry, the primary parameters of the dual CFT(2) can be exactly obtained without the necessity of embedding the four-dimensional Reissner-Nordstrom black hole into five-dimensional spacetime. The duality is further supported by comparing the absorption cross sections and real-time correlators obtained from both the CFT and the gravity sides.
