  The $B_{u}$ ${\to}$ ${\psi}M$ decays are studied with the perturbative QCD
approach, where the psion ${\psi}$ $=$ ${\psi}(2S)$, ${\psi}(3770)$,
${\psi}(4040)$ and ${\psi}(4160)$, and the light meson $M$ $=$ ${\pi}$, $K$,
${\rho}$ and $K^{\ast}$. The factorizable and nonfactorizable contributions,
and the $S$-$D$ wave mixing effects on the psions are considered in the
calculation. With appropriate inputs, the branching ratios for the $B_{u}$
${\to}$ ${\psi}K$ decays are generally coincident with the experimental data
within errors. However, due to the large theoretical and experimental errors,
it is impossible for the moment to give a severe constraint on the $S$-$D$ wave
mixing angles.
