  We derive the chiral effective Lagrangian for heavy-light mesons in the heavy
quark limit from QCD under proper approximations. The low energy constants in
the effective Lagrangian are expressed in terms of the light quark self-energy.
With typical forms of the running coupling constant of QCD and the quark
self-energy obtained from Dyson-Schwinger equations as well as lattice QCD, we
estimate the low energy constants in the model and the strong decay widths. A
comparison with data and some discussions of the numerical results are
presented.
