  We study B meson decays to two charmless baryons in the diquark model,
including strong and electroweak penguins as well as the tree operators. It is
shown that penguin operators can enhance $\bar{B} \to \Bb_s \bar{\Bb}$
considerably, but affect $\bar{B} \to \Bb_1 \bar{\Bb}_2$ only slightly, where
$\Bb_{(1,2)}$ and $\Bb_s$ are non-strange and strange baryons, respectively.
The $\gamma$ dependence of the decay rates due to tree-penguin interference is
illustrated. In principle, some of the $\Bb_s \bar{\Bb}$ modes could dominate
over $\Bb_1 \bar{\Bb}_2$ for $\gamma > 90^\circ$, but in general the effect is
milder than their mesonic counterparts. This is because the $O_6$ operator can
only produce vector but not scalar diquarks, while the opposite is true for
$O_1$ and $O_4$. Predictions from diquark model are compared to those from the
sum rule calculation. The decays $\bar{B} \to \Bb_s \bar{\Bb}_s$ and inclusive
baryonic decays are also discussed.
