  $B^\pm \to (D^0, \bar D^0, D_{CP})K^{*\pm}_{0,2}$ decays are helpful in
determining the CP violation angle $\gamma$, and we analyze these decay
processes within the perturbative QCD approach based on $k_T$ factorization. We
found that the branching ratio of $B^-\to D^0 K^{*-}_0$ can reach the order of
$10^{-4}$, due to the enhancement of nonfactorizable contributions in
color-suppressed $D^0$-emission, while the branching ratio of $B^-\to \bar D^0
K^{*-}_0$ is of the order $10^{-5}$. The ratio of decay amplitudes is about 3
times larger than the one in the channel $B^\pm\to D K^\pm$. Large branching
ratios provide a good opportunity to observe $ B^\pm \to D K^{*\pm}_2$ on the
ongoing and forthcoming experimental facilities and consequently these channels
may be of valuable avail in reducing the errors in the CP violation phase angle
$\gamma$. We also explore the possible time-dependent CP asymmetries of $B_s$
decay into a scalar meson to determine the phase angle $\gamma$.
