  In this paper, a study of light-cone distribution amplitudes (LCDAs) for
$s$-wave heavy meson are presented in both general and heavy quark frameworks.
Within the light-front approach, the leading twist light-cone distribution
amplitudes, $\phi_M(u)$, and their relevant decay constants of heavy
pseudoscalar and vector mesons, $f_M$, have simple relations. These relations
can be further simplified when the heavy quark limit is taken into
consideration. After fixing the parameters that appear in both Gaussian and
power-law wave functions, the corresponding decay constants are calculated and
compared with those of other theoretical approaches. The curves and the first
six $\xi$-moments of $\phi_M(u)$ are plotted and estimated. A conclusion is
drawn from these results: Even though the values of the decay constants of the
distinct mesons are almost equal, the curves of their LCDAs may have quite
large differences, and vice versa. Additionally, in the heavy quark limit, the
leading twist LCDAs, $\Phi_{Qq}(\omega)$ and $\Phi_{Qq}(\omega)$, are compared
with the $B$-meson LCDAs, $\psi_+(\omega)$, suggested by the other theoretical
groups.
