  Motivated by recent data on B-> p pbar K decay, we study various charmless
three-body baryonic B decay modes, including Lambda pbar pi, Sigma0 pbar pi, p
pbar pi, p pbar Kbar0, in a factorization approach. These modes have rates of
order 10^{-6}. There are two mechanisms for the baryon pair production,
current-produced and transition. The behavior of decay spectra from these
baryon production mechanisms can be understood by using QCD counting rules.
Predictions on rates and decay spectra can be checked in the near future.
