  We construct a holographic model of heavy-light mesons by extending the
AdS/QCD to incorporate the behavior of the heavy quark limit. In that limit,
the QCD dynamics is governed by the light quark and the heavy quark simply
plays the role of a static color source. The heavy quark spin symmetry can be
treated as a global symmetry in the AdS bulk. As a consequence, the heavy-light
mesons are mapped to "fermions" in the AdS theory. The light flavor chiral
symmetry is naturally built in by this construction, and its breaking produces
the splitting of the parity-doubled heavy-light meson states. The scaling
dependences of physical quantities on the heavy quark mass in the heavy quark
effective theory are reproduced. The mass spectra and decay constants of the B
and D mesons can be well fit by suitable choices of model parameters. The
couplings between the heavy-light mesons and the pions are also calculated. The
holographic model may capture the essence of the long distance effects of QCD
and can serve as a useful tool for studying the non-perturbative hadronic
matrix elements involving heavy-light mesons.
