  We analyze the effects of the space-like penguin diagrams in two body B
decays $B^-\to K^-{\bar K}^0$ and $B^-\to \pi^-{\bar K}^0$. Special attention
is paid to the operator $Q_6$, whose contribution is large in the BSW model,
but vanishes in the PQCD method in the approximation of neglecting the masses
in the final states. Suppressions of the space-like penguin diagrams are found
in the PQCD method, which implies that the contributions of the space-like
penguins are small compared to those of the time-like penguins.
