  Two-body non-leptonic charmed decays $B_{(s)} \to D_{(s)}P$, $D_{(s)}^*P$,
$D_{(s)}V$ and $D_{(s)}^*V$ are analyzed in perturbative QCD approach, where
$P$ and $V$ denote the light pseudoscalar meson and vector meson, respectively.
We test the $D$ meson wave function by a $\chi^2$ fit with experimental data of
six $B\to DP$ channels. We give the branching ratios of all the charmed B decay
channels, most of which agree with experiments amazingly well. The predicted
$B_s$ decays can be confronted with the future experimental data. By
straightforward calculations, our pQCD approach gives the right relative strong
phase of $a_2/a_1$ with experiments. We also predict the percentage of
transverse polarizations in $B_{(s)} \to D^* V$ decay channels.
