  We present a calculation of the quark distribution amplitudes(DAs), the
Gegenbauer moments, and decay constants for $\pi,\rho,K$ and $K^*$ mesons using
the light-front quark model. While the quark DA for $\pi$ is somewhat broader
than the asymptotic one, that for $\rho$ meson is very close to the asymptotic
one. The quark DAs for $K$ and $K^*$ show asymmetric form due to the flavor
SU(3)-symmetry breaking effect. The decay constants for the transversely
polarized $\rho$ and $K^*$ mesons($f^T_\rho$ and $f^T_{K^*}$) as well as the
longitudinally polarized ones($f_\rho$ and $f_{K^*}$) are also obtained. Our
averaged values for $f^T_V/f_V$, i.e. $(f^T_\rho/f_\rho)_{\rm av}=0.78$ and
$(f^T_{K^*}/f_{K^*})_{\rm av}=0.84$, are found to be consistent with other
model predictions. Especially, our results for the decay constants are in a
good agreement with the SU(6) symmetry relation,
$f^T_{\rho(K^*)}=(f_{\pi(K)}+f_{\rho(K^*)})/2$.
