  In the framework of perturbative QCD approach, we calculate the branching
ratio and CP asymmetry for $B_{s}^0(\bar{B}_{s}) \to \pi^{\pm} K^\mp$ and
$B_{s}(\bar{B}_{s})\to \pi^{0}\bar{K}^{0}(K^{0})$ decays. Besides the usual
factorizable diagrams, both non-factorizable and annihilation type
contributions are taken into account. We find that (a) the branching ratio of
$B_{s}^0(\bar{B}_{s}) \to \pi^{\pm} K^\mp$ is about $(6-10) \times 10^{-6}$;
$Br(B_{s}(\bar{B}_{s})\to \pi^{0}\bar{K}^{0}(K^{0}))$ about $ (1-3) \times
10^{-7}$; and (b) there are large CP asymmetries in the two processes, which
can be tested in the near future LHC-b experiments at CERN and BTeV experiments
at Fermilab.
