  In this paper, we calculate the branching ratios and CP-violating asymmetries
for $B_{s}\to \rho^\pm K^\mp$, $B_{s}\to\rho^{0}\bar{K}^0 $ and
$B_{s}\to\omega\bar{K}^0$ decays in the perturbative QCD (pQCD) factorization
approach. The theoretical predictions for the CP averaged branching ratios of
the considered decays are: $Br(B_{s}\to\rho^\pm K^\mp)\approx 24.7 \times
10^{-6}$, $Br(B_{s}\to\rho^{0}\bar{K}^0) \approx 1.2 \times 10^{-7}$ and
$Br(B_{s} \to\omega\bar{K}^0) \approx 1.7 \times 10^{-7}$; and we also predict
very large direct CP-violating asymmetries for the latter two decay modes:
$A_{CP}^{dir}(\rho^{\pm} K^{\mp})\approx -12 %$,
$A_{CP}^{dir}(\rho^0\bar{K}^0)\approx -92%$,
$A_{CP}^{dir}(\omega^0\bar{K}^0)\approx 81%$,
$A_{CP}^{mix}(\rho^0\bar{K}^0)\approx -36%$, and
$A_{CP}^{mix}(\omega^0\bar{K}^0) \approx -40%$, which can be tested in the
forthcoming LHC-b experiments.
