  We study the structure-dependent contributions to the radiative baryonic $B$
decays of $B \to {\bf B}{\bf \bar B'}\gamma$ in the standard model. We show
that the decay branching ratios of $Br(B \to {\bf B}{\bf \bar B'}\gamma)$ are
$O(10^{-7})$, which are larger than the estimated values of $O(10^{-9})$
induced from inner bremsstrahlung effects of the corresponding two-body modes.
In particular, we find that $Br(B^- \to \Lambda \bar p \gamma)$ is around $1
\times 10^{-6}$, which is close to the pole model estimation but smaller than
the experimental measurement from BELLE.
